1/*
2   SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
3   file Documentation/scsi/st.txt for more information.
4
5   History:
6   Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
7   Contribution and ideas from several people including (in alphabetical
8   order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
9   Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
10   Michael Schaefer, J"org Weule, and Eric Youngdale.
11
12   Copyright 1992 - 2010 Kai Makisara
13   email Kai.Makisara@kolumbus.fi
14
15   Some small formal changes - aeb, 950809
16
17   Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
18 */
19
20static const char *verstr = "20101219";
21
22#include <linux/module.h>
23
24#include <linux/fs.h>
25#include <linux/kernel.h>
26#include <linux/sched.h>
27#include <linux/mm.h>
28#include <linux/init.h>
29#include <linux/string.h>
30#include <linux/slab.h>
31#include <linux/errno.h>
32#include <linux/mtio.h>
33#include <linux/cdrom.h>
34#include <linux/ioctl.h>
35#include <linux/fcntl.h>
36#include <linux/spinlock.h>
37#include <linux/blkdev.h>
38#include <linux/moduleparam.h>
39#include <linux/cdev.h>
40#include <linux/delay.h>
41#include <linux/mutex.h>
42
43#include <asm/uaccess.h>
44#include <asm/dma.h>
45
46#include <scsi/scsi.h>
47#include <scsi/scsi_dbg.h>
48#include <scsi/scsi_device.h>
49#include <scsi/scsi_driver.h>
50#include <scsi/scsi_eh.h>
51#include <scsi/scsi_host.h>
52#include <scsi/scsi_ioctl.h>
53#include <scsi/sg.h>
54
55
56/* The driver prints some debugging information on the console if DEBUG
57   is defined and non-zero. */
58#define DEBUG 0
59
60#if DEBUG
61/* The message level for the debug messages is currently set to KERN_NOTICE
62   so that people can easily see the messages. Later when the debugging messages
63   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
64#define ST_DEB_MSG  KERN_NOTICE
65#define DEB(a) a
66#define DEBC(a) if (debugging) { a ; }
67#else
68#define DEB(a)
69#define DEBC(a)
70#endif
71
72#define ST_KILOBYTE 1024
73
74#include "st_options.h"
75#include "st.h"
76
77static DEFINE_MUTEX(st_mutex);
78static int buffer_kbs;
79static int max_sg_segs;
80static int try_direct_io = TRY_DIRECT_IO;
81static int try_rdio = 1;
82static int try_wdio = 1;
83
84static int st_dev_max;
85static int st_nr_dev;
86
87static struct class *st_sysfs_class;
88
89MODULE_AUTHOR("Kai Makisara");
90MODULE_DESCRIPTION("SCSI tape (st) driver");
91MODULE_LICENSE("GPL");
92MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
93MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
94
95/* Set 'perm' (4th argument) to 0 to disable module_param's definition
96 * of sysfs parameters (which module_param doesn't yet support).
97 * Sysfs parameters defined explicitly later.
98 */
99module_param_named(buffer_kbs, buffer_kbs, int, 0);
100MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
101module_param_named(max_sg_segs, max_sg_segs, int, 0);
102MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
103module_param_named(try_direct_io, try_direct_io, int, 0);
104MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
105
106/* Extra parameters for testing */
107module_param_named(try_rdio, try_rdio, int, 0);
108MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
109module_param_named(try_wdio, try_wdio, int, 0);
110MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
111
112#ifndef MODULE
113static int write_threshold_kbs;  /* retained for compatibility */
114static struct st_dev_parm {
115	char *name;
116	int *val;
117} parms[] __initdata = {
118	{
119		"buffer_kbs", &buffer_kbs
120	},
121	{       /* Retained for compatibility with 2.4 */
122		"write_threshold_kbs", &write_threshold_kbs
123	},
124	{
125		"max_sg_segs", NULL
126	},
127	{
128		"try_direct_io", &try_direct_io
129	}
130};
131#endif
132
133/* Restrict the number of modes so that names for all are assigned */
134#if ST_NBR_MODES > 16
135#error "Maximum number of modes is 16"
136#endif
137/* Bit reversed order to get same names for same minors with all
138   mode counts */
139static const char *st_formats[] = {
140	"",  "r", "k", "s", "l", "t", "o", "u",
141	"m", "v", "p", "x", "a", "y", "q", "z"};
142
143/* The default definitions have been moved to st_options.h */
144
145#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
146
147/* The buffer size should fit into the 24 bits for length in the
148   6-byte SCSI read and write commands. */
149#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
150#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
151#endif
152
153static int debugging = DEBUG;
154
155#define MAX_RETRIES 0
156#define MAX_WRITE_RETRIES 0
157#define MAX_READY_RETRIES 0
158#define NO_TAPE  NOT_READY
159
160#define ST_TIMEOUT (900 * HZ)
161#define ST_LONG_TIMEOUT (14000 * HZ)
162
163/* Remove mode bits and auto-rewind bit (7) */
164#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
165    (iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
166#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
167
168/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
169#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
170  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
171
172/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
173   24 bits) */
174#define SET_DENS_AND_BLK 0x10001
175
176static DEFINE_RWLOCK(st_dev_arr_lock);
177
178static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
179static int st_max_sg_segs = ST_MAX_SG;
180
181static struct scsi_tape **scsi_tapes = NULL;
182
183static int modes_defined;
184
185static int enlarge_buffer(struct st_buffer *, int, int);
186static void clear_buffer(struct st_buffer *);
187static void normalize_buffer(struct st_buffer *);
188static int append_to_buffer(const char __user *, struct st_buffer *, int);
189static int from_buffer(struct st_buffer *, char __user *, int);
190static void move_buffer_data(struct st_buffer *, int);
191
192static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
193			      unsigned long, size_t, int);
194static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
195
196static int st_probe(struct device *);
197static int st_remove(struct device *);
198
199static int do_create_sysfs_files(void);
200static void do_remove_sysfs_files(void);
201static int do_create_class_files(struct scsi_tape *, int, int);
202
203static struct scsi_driver st_template = {
204	.owner			= THIS_MODULE,
205	.gendrv = {
206		.name		= "st",
207		.probe		= st_probe,
208		.remove		= st_remove,
209	},
210};
211
212static int st_compression(struct scsi_tape *, int);
213
214static int find_partition(struct scsi_tape *);
215static int switch_partition(struct scsi_tape *);
216
217static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
218
219static void scsi_tape_release(struct kref *);
220
221#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
222
223static DEFINE_MUTEX(st_ref_mutex);
224
225
226#include "osst_detect.h"
227#ifndef SIGS_FROM_OSST
228#define SIGS_FROM_OSST \
229	{"OnStream", "SC-", "", "osst"}, \
230	{"OnStream", "DI-", "", "osst"}, \
231	{"OnStream", "DP-", "", "osst"}, \
232	{"OnStream", "USB", "", "osst"}, \
233	{"OnStream", "FW-", "", "osst"}
234#endif
235
236static struct scsi_tape *scsi_tape_get(int dev)
237{
238	struct scsi_tape *STp = NULL;
239
240	mutex_lock(&st_ref_mutex);
241	write_lock(&st_dev_arr_lock);
242
243	if (dev < st_dev_max && scsi_tapes != NULL)
244		STp = scsi_tapes[dev];
245	if (!STp) goto out;
246
247	kref_get(&STp->kref);
248
249	if (!STp->device)
250		goto out_put;
251
252	if (scsi_device_get(STp->device))
253		goto out_put;
254
255	goto out;
256
257out_put:
258	kref_put(&STp->kref, scsi_tape_release);
259	STp = NULL;
260out:
261	write_unlock(&st_dev_arr_lock);
262	mutex_unlock(&st_ref_mutex);
263	return STp;
264}
265
266static void scsi_tape_put(struct scsi_tape *STp)
267{
268	struct scsi_device *sdev = STp->device;
269
270	mutex_lock(&st_ref_mutex);
271	kref_put(&STp->kref, scsi_tape_release);
272	scsi_device_put(sdev);
273	mutex_unlock(&st_ref_mutex);
274}
275
276struct st_reject_data {
277	char *vendor;
278	char *model;
279	char *rev;
280	char *driver_hint; /* Name of the correct driver, NULL if unknown */
281};
282
283static struct st_reject_data reject_list[] = {
284	/* {"XXX", "Yy-", "", NULL},  example */
285	SIGS_FROM_OSST,
286	{NULL, }};
287
288/* If the device signature is on the list of incompatible drives, the
289   function returns a pointer to the name of the correct driver (if known) */
290static char * st_incompatible(struct scsi_device* SDp)
291{
292	struct st_reject_data *rp;
293
294	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
295		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
296		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
297		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
298			if (rp->driver_hint)
299				return rp->driver_hint;
300			else
301				return "unknown";
302		}
303	return NULL;
304}
305
306
307static inline char *tape_name(struct scsi_tape *tape)
308{
309	return tape->disk->disk_name;
310}
311
312
313static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
314{
315	const u8 *ucp;
316	const u8 *sense = SRpnt->sense;
317
318	s->have_sense = scsi_normalize_sense(SRpnt->sense,
319				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
320	s->flags = 0;
321
322	if (s->have_sense) {
323		s->deferred = 0;
324		s->remainder_valid =
325			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
326		switch (sense[0] & 0x7f) {
327		case 0x71:
328			s->deferred = 1;
329		case 0x70:
330			s->fixed_format = 1;
331			s->flags = sense[2] & 0xe0;
332			break;
333		case 0x73:
334			s->deferred = 1;
335		case 0x72:
336			s->fixed_format = 0;
337			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
338			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
339			break;
340		}
341	}
342}
343
344
345/* Convert the result to success code */
346static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
347{
348	int result = SRpnt->result;
349	u8 scode;
350	DEB(const char *stp;)
351	char *name = tape_name(STp);
352	struct st_cmdstatus *cmdstatp;
353
354	if (!result)
355		return 0;
356
357	cmdstatp = &STp->buffer->cmdstat;
358	st_analyze_sense(SRpnt, cmdstatp);
359
360	if (cmdstatp->have_sense)
361		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
362	else
363		scode = 0;
364
365        DEB(
366        if (debugging) {
367                printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x\n",
368		       name, result,
369		       SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
370		       SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
371		if (cmdstatp->have_sense)
372			 __scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
373	} ) /* end DEB */
374	if (!debugging) { /* Abnormal conditions for tape */
375		if (!cmdstatp->have_sense)
376			printk(KERN_WARNING
377			       "%s: Error %x (driver bt 0x%x, host bt 0x%x).\n",
378			       name, result, driver_byte(result),
379			       host_byte(result));
380		else if (cmdstatp->have_sense &&
381			 scode != NO_SENSE &&
382			 scode != RECOVERED_ERROR &&
383			 /* scode != UNIT_ATTENTION && */
384			 scode != BLANK_CHECK &&
385			 scode != VOLUME_OVERFLOW &&
386			 SRpnt->cmd[0] != MODE_SENSE &&
387			 SRpnt->cmd[0] != TEST_UNIT_READY) {
388
389			__scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
390		}
391	}
392
393	if (cmdstatp->fixed_format &&
394	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
395		if (STp->cln_sense_value)
396			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
397					       STp->cln_sense_mask) == STp->cln_sense_value);
398		else
399			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
400					       STp->cln_sense_mask) != 0);
401	}
402	if (cmdstatp->have_sense &&
403	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
404		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
405
406	STp->pos_unknown |= STp->device->was_reset;
407
408	if (cmdstatp->have_sense &&
409	    scode == RECOVERED_ERROR
410#if ST_RECOVERED_WRITE_FATAL
411	    && SRpnt->cmd[0] != WRITE_6
412	    && SRpnt->cmd[0] != WRITE_FILEMARKS
413#endif
414	    ) {
415		STp->recover_count++;
416		STp->recover_reg++;
417
418                DEB(
419		if (debugging) {
420			if (SRpnt->cmd[0] == READ_6)
421				stp = "read";
422			else if (SRpnt->cmd[0] == WRITE_6)
423				stp = "write";
424			else
425				stp = "ioctl";
426			printk(ST_DEB_MSG "%s: Recovered %s error (%d).\n", name, stp,
427			       STp->recover_count);
428		} ) /* end DEB */
429
430		if (cmdstatp->flags == 0)
431			return 0;
432	}
433	return (-EIO);
434}
435
436static struct st_request *st_allocate_request(struct scsi_tape *stp)
437{
438	struct st_request *streq;
439
440	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
441	if (streq)
442		streq->stp = stp;
443	else {
444		DEBC(printk(KERN_ERR "%s: Can't get SCSI request.\n",
445			    tape_name(stp)););
446		if (signal_pending(current))
447			stp->buffer->syscall_result = -EINTR;
448		else
449			stp->buffer->syscall_result = -EBUSY;
450	}
451
452	return streq;
453}
454
455static void st_release_request(struct st_request *streq)
456{
457	kfree(streq);
458}
459
460static void st_scsi_execute_end(struct request *req, int uptodate)
461{
462	struct st_request *SRpnt = req->end_io_data;
463	struct scsi_tape *STp = SRpnt->stp;
464	struct bio *tmp;
465
466	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
467	STp->buffer->cmdstat.residual = req->resid_len;
468
469	tmp = SRpnt->bio;
470	if (SRpnt->waiting)
471		complete(SRpnt->waiting);
472
473	blk_rq_unmap_user(tmp);
474	__blk_put_request(req->q, req);
475}
476
477static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
478			   int data_direction, void *buffer, unsigned bufflen,
479			   int timeout, int retries)
480{
481	struct request *req;
482	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
483	int err = 0;
484	int write = (data_direction == DMA_TO_DEVICE);
485
486	req = blk_get_request(SRpnt->stp->device->request_queue, write,
487			      GFP_KERNEL);
488	if (!req)
489		return DRIVER_ERROR << 24;
490
491	req->cmd_type = REQ_TYPE_BLOCK_PC;
492	req->cmd_flags |= REQ_QUIET;
493
494	mdata->null_mapped = 1;
495
496	if (bufflen) {
497		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
498				      GFP_KERNEL);
499		if (err) {
500			blk_put_request(req);
501			return DRIVER_ERROR << 24;
502		}
503	}
504
505	SRpnt->bio = req->bio;
506	req->cmd_len = COMMAND_SIZE(cmd[0]);
507	memset(req->cmd, 0, BLK_MAX_CDB);
508	memcpy(req->cmd, cmd, req->cmd_len);
509	req->sense = SRpnt->sense;
510	req->sense_len = 0;
511	req->timeout = timeout;
512	req->retries = retries;
513	req->end_io_data = SRpnt;
514
515	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
516	return 0;
517}
518
519/* Do the scsi command. Waits until command performed if do_wait is true.
520   Otherwise write_behind_check() is used to check that the command
521   has finished. */
522static struct st_request *
523st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
524	   int bytes, int direction, int timeout, int retries, int do_wait)
525{
526	struct completion *waiting;
527	struct rq_map_data *mdata = &STp->buffer->map_data;
528	int ret;
529
530	/* if async, make sure there's no command outstanding */
531	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
532		printk(KERN_ERR "%s: Async command already active.\n",
533		       tape_name(STp));
534		if (signal_pending(current))
535			(STp->buffer)->syscall_result = (-EINTR);
536		else
537			(STp->buffer)->syscall_result = (-EBUSY);
538		return NULL;
539	}
540
541	if (!SRpnt) {
542		SRpnt = st_allocate_request(STp);
543		if (!SRpnt)
544			return NULL;
545	}
546
547	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
548	   which IO is outstanding. It's nulled out when the IO completes. */
549	if (!do_wait)
550		(STp->buffer)->last_SRpnt = SRpnt;
551
552	waiting = &STp->wait;
553	init_completion(waiting);
554	SRpnt->waiting = waiting;
555
556	if (STp->buffer->do_dio) {
557		mdata->page_order = 0;
558		mdata->nr_entries = STp->buffer->sg_segs;
559		mdata->pages = STp->buffer->mapped_pages;
560	} else {
561		mdata->page_order = STp->buffer->reserved_page_order;
562		mdata->nr_entries =
563			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
564		mdata->pages = STp->buffer->reserved_pages;
565		mdata->offset = 0;
566	}
567
568	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
569	STp->buffer->cmdstat.have_sense = 0;
570	STp->buffer->syscall_result = 0;
571
572	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
573			      retries);
574	if (ret) {
575		/* could not allocate the buffer or request was too large */
576		(STp->buffer)->syscall_result = (-EBUSY);
577		(STp->buffer)->last_SRpnt = NULL;
578	} else if (do_wait) {
579		wait_for_completion(waiting);
580		SRpnt->waiting = NULL;
581		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
582	}
583
584	return SRpnt;
585}
586
587
588/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
589   write has been correct but EOM early warning reached, -EIO if write ended in
590   error or zero if write successful. Asynchronous writes are used only in
591   variable block mode. */
592static int write_behind_check(struct scsi_tape * STp)
593{
594	int retval = 0;
595	struct st_buffer *STbuffer;
596	struct st_partstat *STps;
597	struct st_cmdstatus *cmdstatp;
598	struct st_request *SRpnt;
599
600	STbuffer = STp->buffer;
601	if (!STbuffer->writing)
602		return 0;
603
604        DEB(
605	if (STp->write_pending)
606		STp->nbr_waits++;
607	else
608		STp->nbr_finished++;
609        ) /* end DEB */
610
611	wait_for_completion(&(STp->wait));
612	SRpnt = STbuffer->last_SRpnt;
613	STbuffer->last_SRpnt = NULL;
614	SRpnt->waiting = NULL;
615
616	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
617	st_release_request(SRpnt);
618
619	STbuffer->buffer_bytes -= STbuffer->writing;
620	STps = &(STp->ps[STp->partition]);
621	if (STps->drv_block >= 0) {
622		if (STp->block_size == 0)
623			STps->drv_block++;
624		else
625			STps->drv_block += STbuffer->writing / STp->block_size;
626	}
627
628	cmdstatp = &STbuffer->cmdstat;
629	if (STbuffer->syscall_result) {
630		retval = -EIO;
631		if (cmdstatp->have_sense && !cmdstatp->deferred &&
632		    (cmdstatp->flags & SENSE_EOM) &&
633		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
634		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
635			/* EOM at write-behind, has all data been written? */
636			if (!cmdstatp->remainder_valid ||
637			    cmdstatp->uremainder64 == 0)
638				retval = -ENOSPC;
639		}
640		if (retval == -EIO)
641			STps->drv_block = -1;
642	}
643	STbuffer->writing = 0;
644
645	DEB(if (debugging && retval)
646	    printk(ST_DEB_MSG "%s: Async write error %x, return value %d.\n",
647		   tape_name(STp), STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
648
649	return retval;
650}
651
652
653/* Step over EOF if it has been inadvertently crossed (ioctl not used because
654   it messes up the block number). */
655static int cross_eof(struct scsi_tape * STp, int forward)
656{
657	struct st_request *SRpnt;
658	unsigned char cmd[MAX_COMMAND_SIZE];
659
660	cmd[0] = SPACE;
661	cmd[1] = 0x01;		/* Space FileMarks */
662	if (forward) {
663		cmd[2] = cmd[3] = 0;
664		cmd[4] = 1;
665	} else
666		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
667	cmd[5] = 0;
668
669        DEBC(printk(ST_DEB_MSG "%s: Stepping over filemark %s.\n",
670		   tape_name(STp), forward ? "forward" : "backward"));
671
672	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
673			   STp->device->request_queue->rq_timeout,
674			   MAX_RETRIES, 1);
675	if (!SRpnt)
676		return (STp->buffer)->syscall_result;
677
678	st_release_request(SRpnt);
679	SRpnt = NULL;
680
681	if ((STp->buffer)->cmdstat.midlevel_result != 0)
682		printk(KERN_ERR "%s: Stepping over filemark %s failed.\n",
683		   tape_name(STp), forward ? "forward" : "backward");
684
685	return (STp->buffer)->syscall_result;
686}
687
688
689/* Flush the write buffer (never need to write if variable blocksize). */
690static int st_flush_write_buffer(struct scsi_tape * STp)
691{
692	int transfer, blks;
693	int result;
694	unsigned char cmd[MAX_COMMAND_SIZE];
695	struct st_request *SRpnt;
696	struct st_partstat *STps;
697
698	result = write_behind_check(STp);
699	if (result)
700		return result;
701
702	result = 0;
703	if (STp->dirty == 1) {
704
705		transfer = STp->buffer->buffer_bytes;
706                DEBC(printk(ST_DEB_MSG "%s: Flushing %d bytes.\n",
707                               tape_name(STp), transfer));
708
709		memset(cmd, 0, MAX_COMMAND_SIZE);
710		cmd[0] = WRITE_6;
711		cmd[1] = 1;
712		blks = transfer / STp->block_size;
713		cmd[2] = blks >> 16;
714		cmd[3] = blks >> 8;
715		cmd[4] = blks;
716
717		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
718				   STp->device->request_queue->rq_timeout,
719				   MAX_WRITE_RETRIES, 1);
720		if (!SRpnt)
721			return (STp->buffer)->syscall_result;
722
723		STps = &(STp->ps[STp->partition]);
724		if ((STp->buffer)->syscall_result != 0) {
725			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
726
727			if (cmdstatp->have_sense && !cmdstatp->deferred &&
728			    (cmdstatp->flags & SENSE_EOM) &&
729			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
730			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
731			    (!cmdstatp->remainder_valid ||
732			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
733				STp->dirty = 0;
734				(STp->buffer)->buffer_bytes = 0;
735				if (STps->drv_block >= 0)
736					STps->drv_block += blks;
737				result = (-ENOSPC);
738			} else {
739				printk(KERN_ERR "%s: Error on flush.\n",
740                                       tape_name(STp));
741				STps->drv_block = (-1);
742				result = (-EIO);
743			}
744		} else {
745			if (STps->drv_block >= 0)
746				STps->drv_block += blks;
747			STp->dirty = 0;
748			(STp->buffer)->buffer_bytes = 0;
749		}
750		st_release_request(SRpnt);
751		SRpnt = NULL;
752	}
753	return result;
754}
755
756
757/* Flush the tape buffer. The tape will be positioned correctly unless
758   seek_next is true. */
759static int flush_buffer(struct scsi_tape *STp, int seek_next)
760{
761	int backspace, result;
762	struct st_buffer *STbuffer;
763	struct st_partstat *STps;
764
765	STbuffer = STp->buffer;
766
767	/*
768	 * If there was a bus reset, block further access
769	 * to this device.
770	 */
771	if (STp->pos_unknown)
772		return (-EIO);
773
774	if (STp->ready != ST_READY)
775		return 0;
776	STps = &(STp->ps[STp->partition]);
777	if (STps->rw == ST_WRITING)	/* Writing */
778		return st_flush_write_buffer(STp);
779
780	if (STp->block_size == 0)
781		return 0;
782
783	backspace = ((STp->buffer)->buffer_bytes +
784		     (STp->buffer)->read_pointer) / STp->block_size -
785	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
786	    STp->block_size;
787	(STp->buffer)->buffer_bytes = 0;
788	(STp->buffer)->read_pointer = 0;
789	result = 0;
790	if (!seek_next) {
791		if (STps->eof == ST_FM_HIT) {
792			result = cross_eof(STp, 0);	/* Back over the EOF hit */
793			if (!result)
794				STps->eof = ST_NOEOF;
795			else {
796				if (STps->drv_file >= 0)
797					STps->drv_file++;
798				STps->drv_block = 0;
799			}
800		}
801		if (!result && backspace > 0)
802			result = st_int_ioctl(STp, MTBSR, backspace);
803	} else if (STps->eof == ST_FM_HIT) {
804		if (STps->drv_file >= 0)
805			STps->drv_file++;
806		STps->drv_block = 0;
807		STps->eof = ST_NOEOF;
808	}
809	return result;
810
811}
812
813/* Set the mode parameters */
814static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
815{
816	int set_it = 0;
817	unsigned long arg;
818	char *name = tape_name(STp);
819
820	if (!STp->density_changed &&
821	    STm->default_density >= 0 &&
822	    STm->default_density != STp->density) {
823		arg = STm->default_density;
824		set_it = 1;
825	} else
826		arg = STp->density;
827	arg <<= MT_ST_DENSITY_SHIFT;
828	if (!STp->blksize_changed &&
829	    STm->default_blksize >= 0 &&
830	    STm->default_blksize != STp->block_size) {
831		arg |= STm->default_blksize;
832		set_it = 1;
833	} else
834		arg |= STp->block_size;
835	if (set_it &&
836	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
837		printk(KERN_WARNING
838		       "%s: Can't set default block size to %d bytes and density %x.\n",
839		       name, STm->default_blksize, STm->default_density);
840		if (modes_defined)
841			return (-EINVAL);
842	}
843	return 0;
844}
845
846
847/* Lock or unlock the drive door. Don't use when st_request allocated. */
848static int do_door_lock(struct scsi_tape * STp, int do_lock)
849{
850	int retval, cmd;
851	DEB(char *name = tape_name(STp);)
852
853
854	cmd = do_lock ? SCSI_IOCTL_DOORLOCK : SCSI_IOCTL_DOORUNLOCK;
855	DEBC(printk(ST_DEB_MSG "%s: %socking drive door.\n", name,
856		    do_lock ? "L" : "Unl"));
857	retval = scsi_ioctl(STp->device, cmd, NULL);
858	if (!retval) {
859		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
860	}
861	else {
862		STp->door_locked = ST_LOCK_FAILS;
863	}
864	return retval;
865}
866
867
868/* Set the internal state after reset */
869static void reset_state(struct scsi_tape *STp)
870{
871	int i;
872	struct st_partstat *STps;
873
874	STp->pos_unknown = 0;
875	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
876		STps = &(STp->ps[i]);
877		STps->rw = ST_IDLE;
878		STps->eof = ST_NOEOF;
879		STps->at_sm = 0;
880		STps->last_block_valid = 0;
881		STps->drv_block = -1;
882		STps->drv_file = -1;
883	}
884	if (STp->can_partitions) {
885		STp->partition = find_partition(STp);
886		if (STp->partition < 0)
887			STp->partition = 0;
888		STp->new_partition = STp->partition;
889	}
890}
891
892/* Test if the drive is ready. Returns either one of the codes below or a negative system
893   error code. */
894#define CHKRES_READY       0
895#define CHKRES_NEW_SESSION 1
896#define CHKRES_NOT_READY   2
897#define CHKRES_NO_TAPE     3
898
899#define MAX_ATTENTIONS    10
900
901static int test_ready(struct scsi_tape *STp, int do_wait)
902{
903	int attentions, waits, max_wait, scode;
904	int retval = CHKRES_READY, new_session = 0;
905	unsigned char cmd[MAX_COMMAND_SIZE];
906	struct st_request *SRpnt = NULL;
907	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
908
909	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
910
911	for (attentions=waits=0; ; ) {
912		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
913		cmd[0] = TEST_UNIT_READY;
914		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
915				   STp->long_timeout, MAX_READY_RETRIES, 1);
916
917		if (!SRpnt) {
918			retval = (STp->buffer)->syscall_result;
919			break;
920		}
921
922		if (cmdstatp->have_sense) {
923
924			scode = cmdstatp->sense_hdr.sense_key;
925
926			if (scode == UNIT_ATTENTION) { /* New media? */
927				new_session = 1;
928				if (attentions < MAX_ATTENTIONS) {
929					attentions++;
930					continue;
931				}
932				else {
933					retval = (-EIO);
934					break;
935				}
936			}
937
938			if (scode == NOT_READY) {
939				if (waits < max_wait) {
940					if (msleep_interruptible(1000)) {
941						retval = (-EINTR);
942						break;
943					}
944					waits++;
945					continue;
946				}
947				else {
948					if ((STp->device)->scsi_level >= SCSI_2 &&
949					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
950						retval = CHKRES_NO_TAPE;
951					else
952						retval = CHKRES_NOT_READY;
953					break;
954				}
955			}
956		}
957
958		retval = (STp->buffer)->syscall_result;
959		if (!retval)
960			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
961		break;
962	}
963
964	if (SRpnt != NULL)
965		st_release_request(SRpnt);
966	return retval;
967}
968
969
970/* See if the drive is ready and gather information about the tape. Return values:
971   < 0   negative error code from errno.h
972   0     drive ready
973   1     drive not ready (possibly no tape)
974*/
975static int check_tape(struct scsi_tape *STp, struct file *filp)
976{
977	int i, retval, new_session = 0, do_wait;
978	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
979	unsigned short st_flags = filp->f_flags;
980	struct st_request *SRpnt = NULL;
981	struct st_modedef *STm;
982	struct st_partstat *STps;
983	char *name = tape_name(STp);
984	struct inode *inode = filp->f_path.dentry->d_inode;
985	int mode = TAPE_MODE(inode);
986
987	STp->ready = ST_READY;
988
989	if (mode != STp->current_mode) {
990                DEBC(printk(ST_DEB_MSG "%s: Mode change from %d to %d.\n",
991			       name, STp->current_mode, mode));
992		new_session = 1;
993		STp->current_mode = mode;
994	}
995	STm = &(STp->modes[STp->current_mode]);
996
997	saved_cleaning = STp->cleaning_req;
998	STp->cleaning_req = 0;
999
1000	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1001	retval = test_ready(STp, do_wait);
1002
1003	if (retval < 0)
1004	    goto err_out;
1005
1006	if (retval == CHKRES_NEW_SESSION) {
1007		STp->pos_unknown = 0;
1008		STp->partition = STp->new_partition = 0;
1009		if (STp->can_partitions)
1010			STp->nbr_partitions = 1; /* This guess will be updated later
1011                                                    if necessary */
1012		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1013			STps = &(STp->ps[i]);
1014			STps->rw = ST_IDLE;
1015			STps->eof = ST_NOEOF;
1016			STps->at_sm = 0;
1017			STps->last_block_valid = 0;
1018			STps->drv_block = 0;
1019			STps->drv_file = 0;
1020		}
1021		new_session = 1;
1022	}
1023	else {
1024		STp->cleaning_req |= saved_cleaning;
1025
1026		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1027			if (retval == CHKRES_NO_TAPE)
1028				STp->ready = ST_NO_TAPE;
1029			else
1030				STp->ready = ST_NOT_READY;
1031
1032			STp->density = 0;	/* Clear the erroneous "residue" */
1033			STp->write_prot = 0;
1034			STp->block_size = 0;
1035			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1036			STp->partition = STp->new_partition = 0;
1037			STp->door_locked = ST_UNLOCKED;
1038			return CHKRES_NOT_READY;
1039		}
1040	}
1041
1042	if (STp->omit_blklims)
1043		STp->min_block = STp->max_block = (-1);
1044	else {
1045		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1046		cmd[0] = READ_BLOCK_LIMITS;
1047
1048		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1049				   STp->device->request_queue->rq_timeout,
1050				   MAX_READY_RETRIES, 1);
1051		if (!SRpnt) {
1052			retval = (STp->buffer)->syscall_result;
1053			goto err_out;
1054		}
1055
1056		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1057			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1058			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1059			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1060			    (STp->buffer)->b_data[5];
1061			if ( DEB( debugging || ) !STp->inited)
1062				printk(KERN_INFO
1063                                       "%s: Block limits %d - %d bytes.\n", name,
1064                                       STp->min_block, STp->max_block);
1065		} else {
1066			STp->min_block = STp->max_block = (-1);
1067                        DEBC(printk(ST_DEB_MSG "%s: Can't read block limits.\n",
1068                                       name));
1069		}
1070	}
1071
1072	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1073	cmd[0] = MODE_SENSE;
1074	cmd[4] = 12;
1075
1076	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1077			   STp->device->request_queue->rq_timeout,
1078			   MAX_READY_RETRIES, 1);
1079	if (!SRpnt) {
1080		retval = (STp->buffer)->syscall_result;
1081		goto err_out;
1082	}
1083
1084	if ((STp->buffer)->syscall_result != 0) {
1085                DEBC(printk(ST_DEB_MSG "%s: No Mode Sense.\n", name));
1086		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1087		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1088		STp->drv_write_prot = 0;
1089	} else {
1090                DEBC(printk(ST_DEB_MSG
1091                            "%s: Mode sense. Length %d, medium %x, WBS %x, BLL %d\n",
1092                            name,
1093                            (STp->buffer)->b_data[0], (STp->buffer)->b_data[1],
1094                            (STp->buffer)->b_data[2], (STp->buffer)->b_data[3]));
1095
1096		if ((STp->buffer)->b_data[3] >= 8) {
1097			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1098			STp->density = (STp->buffer)->b_data[4];
1099			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1100			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1101                        DEBC(printk(ST_DEB_MSG
1102                                    "%s: Density %x, tape length: %x, drv buffer: %d\n",
1103                                    name, STp->density, (STp->buffer)->b_data[5] * 65536 +
1104                                    (STp->buffer)->b_data[6] * 256 + (STp->buffer)->b_data[7],
1105                                    STp->drv_buffer));
1106		}
1107		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1108		if (!STp->drv_buffer && STp->immediate_filemark) {
1109			printk(KERN_WARNING
1110			    "%s: non-buffered tape: disabling writing immediate filemarks\n",
1111			    name);
1112			STp->immediate_filemark = 0;
1113		}
1114	}
1115	st_release_request(SRpnt);
1116	SRpnt = NULL;
1117        STp->inited = 1;
1118
1119	if (STp->block_size > 0)
1120		(STp->buffer)->buffer_blocks =
1121                        (STp->buffer)->buffer_size / STp->block_size;
1122	else
1123		(STp->buffer)->buffer_blocks = 1;
1124	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1125
1126        DEBC(printk(ST_DEB_MSG
1127                       "%s: Block size: %d, buffer size: %d (%d blocks).\n", name,
1128		       STp->block_size, (STp->buffer)->buffer_size,
1129		       (STp->buffer)->buffer_blocks));
1130
1131	if (STp->drv_write_prot) {
1132		STp->write_prot = 1;
1133
1134                DEBC(printk(ST_DEB_MSG "%s: Write protected\n", name));
1135
1136		if (do_wait &&
1137		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1138		     (st_flags & O_ACCMODE) == O_RDWR)) {
1139			retval = (-EROFS);
1140			goto err_out;
1141		}
1142	}
1143
1144	if (STp->can_partitions && STp->nbr_partitions < 1) {
1145		/* This code is reached when the device is opened for the first time
1146		   after the driver has been initialized with tape in the drive and the
1147		   partition support has been enabled. */
1148                DEBC(printk(ST_DEB_MSG
1149                            "%s: Updating partition number in status.\n", name));
1150		if ((STp->partition = find_partition(STp)) < 0) {
1151			retval = STp->partition;
1152			goto err_out;
1153		}
1154		STp->new_partition = STp->partition;
1155		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1156	}
1157
1158	if (new_session) {	/* Change the drive parameters for the new mode */
1159		STp->density_changed = STp->blksize_changed = 0;
1160		STp->compression_changed = 0;
1161		if (!(STm->defaults_for_writes) &&
1162		    (retval = set_mode_densblk(STp, STm)) < 0)
1163		    goto err_out;
1164
1165		if (STp->default_drvbuffer != 0xff) {
1166			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1167				printk(KERN_WARNING
1168                                       "%s: Can't set default drive buffering to %d.\n",
1169				       name, STp->default_drvbuffer);
1170		}
1171	}
1172
1173	return CHKRES_READY;
1174
1175 err_out:
1176	return retval;
1177}
1178
1179
1180/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1181   module count. */
1182static int st_open(struct inode *inode, struct file *filp)
1183{
1184	int i, retval = (-EIO);
1185	int resumed = 0;
1186	struct scsi_tape *STp;
1187	struct st_partstat *STps;
1188	int dev = TAPE_NR(inode);
1189	char *name;
1190
1191	mutex_lock(&st_mutex);
1192	/*
1193	 * We really want to do nonseekable_open(inode, filp); here, but some
1194	 * versions of tar incorrectly call lseek on tapes and bail out if that
1195	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1196	 */
1197	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1198
1199	if (!(STp = scsi_tape_get(dev))) {
1200		mutex_unlock(&st_mutex);
1201		return -ENXIO;
1202	}
1203
1204	write_lock(&st_dev_arr_lock);
1205	filp->private_data = STp;
1206	name = tape_name(STp);
1207
1208	if (STp->in_use) {
1209		write_unlock(&st_dev_arr_lock);
1210		scsi_tape_put(STp);
1211		mutex_unlock(&st_mutex);
1212		DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); )
1213		return (-EBUSY);
1214	}
1215
1216	STp->in_use = 1;
1217	write_unlock(&st_dev_arr_lock);
1218	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1219
1220	if (scsi_autopm_get_device(STp->device) < 0) {
1221		retval = -EIO;
1222		goto err_out;
1223	}
1224	resumed = 1;
1225	if (!scsi_block_when_processing_errors(STp->device)) {
1226		retval = (-ENXIO);
1227		goto err_out;
1228	}
1229
1230	/* See that we have at least a one page buffer available */
1231	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1232		printk(KERN_WARNING "%s: Can't allocate one page tape buffer.\n",
1233		       name);
1234		retval = (-EOVERFLOW);
1235		goto err_out;
1236	}
1237
1238	(STp->buffer)->cleared = 0;
1239	(STp->buffer)->writing = 0;
1240	(STp->buffer)->syscall_result = 0;
1241
1242	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1243
1244	STp->dirty = 0;
1245	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1246		STps = &(STp->ps[i]);
1247		STps->rw = ST_IDLE;
1248	}
1249	STp->try_dio_now = STp->try_dio;
1250	STp->recover_count = 0;
1251	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1252	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1253
1254	retval = check_tape(STp, filp);
1255	if (retval < 0)
1256		goto err_out;
1257	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1258	    retval != CHKRES_READY) {
1259		if (STp->ready == NO_TAPE)
1260			retval = (-ENOMEDIUM);
1261		else
1262			retval = (-EIO);
1263		goto err_out;
1264	}
1265	mutex_unlock(&st_mutex);
1266	return 0;
1267
1268 err_out:
1269	normalize_buffer(STp->buffer);
1270	STp->in_use = 0;
1271	scsi_tape_put(STp);
1272	if (resumed)
1273		scsi_autopm_put_device(STp->device);
1274	mutex_unlock(&st_mutex);
1275	return retval;
1276
1277}
1278
1279
1280/* Flush the tape buffer before close */
1281static int st_flush(struct file *filp, fl_owner_t id)
1282{
1283	int result = 0, result2;
1284	unsigned char cmd[MAX_COMMAND_SIZE];
1285	struct st_request *SRpnt;
1286	struct scsi_tape *STp = filp->private_data;
1287	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1288	struct st_partstat *STps = &(STp->ps[STp->partition]);
1289	char *name = tape_name(STp);
1290
1291	if (file_count(filp) > 1)
1292		return 0;
1293
1294	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1295		result = st_flush_write_buffer(STp);
1296		if (result != 0 && result != (-ENOSPC))
1297			goto out;
1298	}
1299
1300	if (STp->can_partitions &&
1301	    (result2 = switch_partition(STp)) < 0) {
1302                DEBC(printk(ST_DEB_MSG
1303                               "%s: switch_partition at close failed.\n", name));
1304		if (result == 0)
1305			result = result2;
1306		goto out;
1307	}
1308
1309	DEBC( if (STp->nbr_requests)
1310		printk(KERN_DEBUG "%s: Number of r/w requests %d, dio used in %d, pages %d.\n",
1311		       name, STp->nbr_requests, STp->nbr_dio, STp->nbr_pages));
1312
1313	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1314		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1315
1316                DEBC(printk(ST_DEB_MSG "%s: Async write waits %d, finished %d.\n",
1317                            name, STp->nbr_waits, STp->nbr_finished);
1318		)
1319
1320		memset(cmd, 0, MAX_COMMAND_SIZE);
1321		cmd[0] = WRITE_FILEMARKS;
1322		if (STp->immediate_filemark)
1323			cmd[1] = 1;
1324		cmd[4] = 1 + STp->two_fm;
1325
1326		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1327				   STp->device->request_queue->rq_timeout,
1328				   MAX_WRITE_RETRIES, 1);
1329		if (!SRpnt) {
1330			result = (STp->buffer)->syscall_result;
1331			goto out;
1332		}
1333
1334		if (STp->buffer->syscall_result == 0 ||
1335		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1336		     (cmdstatp->flags & SENSE_EOM) &&
1337		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1338		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1339		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1340			/* Write successful at EOM */
1341			st_release_request(SRpnt);
1342			SRpnt = NULL;
1343			if (STps->drv_file >= 0)
1344				STps->drv_file++;
1345			STps->drv_block = 0;
1346			if (STp->two_fm)
1347				cross_eof(STp, 0);
1348			STps->eof = ST_FM;
1349		}
1350		else { /* Write error */
1351			st_release_request(SRpnt);
1352			SRpnt = NULL;
1353			printk(KERN_ERR "%s: Error on write filemark.\n", name);
1354			if (result == 0)
1355				result = (-EIO);
1356		}
1357
1358                DEBC(printk(ST_DEB_MSG "%s: Buffer flushed, %d EOF(s) written\n",
1359                            name, cmd[4]));
1360	} else if (!STp->rew_at_close) {
1361		STps = &(STp->ps[STp->partition]);
1362		if (!STm->sysv || STps->rw != ST_READING) {
1363			if (STp->can_bsr)
1364				result = flush_buffer(STp, 0);
1365			else if (STps->eof == ST_FM_HIT) {
1366				result = cross_eof(STp, 0);
1367				if (result) {
1368					if (STps->drv_file >= 0)
1369						STps->drv_file++;
1370					STps->drv_block = 0;
1371					STps->eof = ST_FM;
1372				} else
1373					STps->eof = ST_NOEOF;
1374			}
1375		} else if ((STps->eof == ST_NOEOF &&
1376			    !(result = cross_eof(STp, 1))) ||
1377			   STps->eof == ST_FM_HIT) {
1378			if (STps->drv_file >= 0)
1379				STps->drv_file++;
1380			STps->drv_block = 0;
1381			STps->eof = ST_FM;
1382		}
1383	}
1384
1385      out:
1386	if (STp->rew_at_close) {
1387		result2 = st_int_ioctl(STp, MTREW, 1);
1388		if (result == 0)
1389			result = result2;
1390	}
1391	return result;
1392}
1393
1394
1395/* Close the device and release it. BKL is not needed: this is the only thread
1396   accessing this tape. */
1397static int st_release(struct inode *inode, struct file *filp)
1398{
1399	int result = 0;
1400	struct scsi_tape *STp = filp->private_data;
1401
1402	if (STp->door_locked == ST_LOCKED_AUTO)
1403		do_door_lock(STp, 0);
1404
1405	normalize_buffer(STp->buffer);
1406	write_lock(&st_dev_arr_lock);
1407	STp->in_use = 0;
1408	write_unlock(&st_dev_arr_lock);
1409	scsi_autopm_put_device(STp->device);
1410	scsi_tape_put(STp);
1411
1412	return result;
1413}
1414
1415/* The checks common to both reading and writing */
1416static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1417{
1418	ssize_t retval = 0;
1419
1420	/*
1421	 * If we are in the middle of error recovery, don't let anyone
1422	 * else try and use this device.  Also, if error recovery fails, it
1423	 * may try and take the device offline, in which case all further
1424	 * access to the device is prohibited.
1425	 */
1426	if (!scsi_block_when_processing_errors(STp->device)) {
1427		retval = (-ENXIO);
1428		goto out;
1429	}
1430
1431	if (STp->ready != ST_READY) {
1432		if (STp->ready == ST_NO_TAPE)
1433			retval = (-ENOMEDIUM);
1434		else
1435			retval = (-EIO);
1436		goto out;
1437	}
1438
1439	if (! STp->modes[STp->current_mode].defined) {
1440		retval = (-ENXIO);
1441		goto out;
1442	}
1443
1444
1445	/*
1446	 * If there was a bus reset, block further access
1447	 * to this device.
1448	 */
1449	if (STp->pos_unknown) {
1450		retval = (-EIO);
1451		goto out;
1452	}
1453
1454	if (count == 0)
1455		goto out;
1456
1457        DEB(
1458	if (!STp->in_use) {
1459		printk(ST_DEB_MSG "%s: Incorrect device.\n", tape_name(STp));
1460		retval = (-EIO);
1461		goto out;
1462	} ) /* end DEB */
1463
1464	if (STp->can_partitions &&
1465	    (retval = switch_partition(STp)) < 0)
1466		goto out;
1467
1468	if (STp->block_size == 0 && STp->max_block > 0 &&
1469	    (count < STp->min_block || count > STp->max_block)) {
1470		retval = (-EINVAL);
1471		goto out;
1472	}
1473
1474	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1475	    !do_door_lock(STp, 1))
1476		STp->door_locked = ST_LOCKED_AUTO;
1477
1478 out:
1479	return retval;
1480}
1481
1482
1483static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1484			   size_t count, int is_read)
1485{
1486	int i, bufsize, retval = 0;
1487	struct st_buffer *STbp = STp->buffer;
1488
1489	if (is_read)
1490		i = STp->try_dio_now && try_rdio;
1491	else
1492		i = STp->try_dio_now && try_wdio;
1493
1494	if (i && ((unsigned long)buf & queue_dma_alignment(
1495					STp->device->request_queue)) == 0) {
1496		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1497				       count, (is_read ? READ : WRITE));
1498		if (i > 0) {
1499			STbp->do_dio = i;
1500			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1501		}
1502		else
1503			STbp->do_dio = 0;  /* fall back to buffering with any error */
1504		STbp->sg_segs = STbp->do_dio;
1505		DEB(
1506		     if (STbp->do_dio) {
1507			STp->nbr_dio++;
1508			STp->nbr_pages += STbp->do_dio;
1509		     }
1510		)
1511	} else
1512		STbp->do_dio = 0;
1513	DEB( STp->nbr_requests++; )
1514
1515	if (!STbp->do_dio) {
1516		if (STp->block_size)
1517			bufsize = STp->block_size > st_fixed_buffer_size ?
1518				STp->block_size : st_fixed_buffer_size;
1519		else {
1520			bufsize = count;
1521			/* Make sure that data from previous user is not leaked even if
1522			   HBA does not return correct residual */
1523			if (is_read && STp->sili && !STbp->cleared)
1524				clear_buffer(STbp);
1525		}
1526
1527		if (bufsize > STbp->buffer_size &&
1528		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1529			printk(KERN_WARNING "%s: Can't allocate %d byte tape buffer.\n",
1530			       tape_name(STp), bufsize);
1531			retval = (-EOVERFLOW);
1532			goto out;
1533		}
1534		if (STp->block_size)
1535			STbp->buffer_blocks = bufsize / STp->block_size;
1536	}
1537
1538 out:
1539	return retval;
1540}
1541
1542
1543/* Can be called more than once after each setup_buffer() */
1544static void release_buffering(struct scsi_tape *STp, int is_read)
1545{
1546	struct st_buffer *STbp;
1547
1548	STbp = STp->buffer;
1549	if (STbp->do_dio) {
1550		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1551		STbp->do_dio = 0;
1552		STbp->sg_segs = 0;
1553	}
1554}
1555
1556
1557/* Write command */
1558static ssize_t
1559st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1560{
1561	ssize_t total;
1562	ssize_t i, do_count, blks, transfer;
1563	ssize_t retval;
1564	int undone, retry_eot = 0, scode;
1565	int async_write;
1566	unsigned char cmd[MAX_COMMAND_SIZE];
1567	const char __user *b_point;
1568	struct st_request *SRpnt = NULL;
1569	struct scsi_tape *STp = filp->private_data;
1570	struct st_modedef *STm;
1571	struct st_partstat *STps;
1572	struct st_buffer *STbp;
1573	char *name = tape_name(STp);
1574
1575	if (mutex_lock_interruptible(&STp->lock))
1576		return -ERESTARTSYS;
1577
1578	retval = rw_checks(STp, filp, count);
1579	if (retval || count == 0)
1580		goto out;
1581
1582	/* Write must be integral number of blocks */
1583	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1584		printk(KERN_WARNING "%s: Write not multiple of tape block size.\n",
1585		       name);
1586		retval = (-EINVAL);
1587		goto out;
1588	}
1589
1590	STm = &(STp->modes[STp->current_mode]);
1591	STps = &(STp->ps[STp->partition]);
1592
1593	if (STp->write_prot) {
1594		retval = (-EACCES);
1595		goto out;
1596	}
1597
1598
1599	if (STps->rw == ST_READING) {
1600		retval = flush_buffer(STp, 0);
1601		if (retval)
1602			goto out;
1603		STps->rw = ST_WRITING;
1604	} else if (STps->rw != ST_WRITING &&
1605		   STps->drv_file == 0 && STps->drv_block == 0) {
1606		if ((retval = set_mode_densblk(STp, STm)) < 0)
1607			goto out;
1608		if (STm->default_compression != ST_DONT_TOUCH &&
1609		    !(STp->compression_changed)) {
1610			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1611				printk(KERN_WARNING "%s: Can't set default compression.\n",
1612				       name);
1613				if (modes_defined) {
1614					retval = (-EINVAL);
1615					goto out;
1616				}
1617			}
1618		}
1619	}
1620
1621	STbp = STp->buffer;
1622	i = write_behind_check(STp);
1623	if (i) {
1624		if (i == -ENOSPC)
1625			STps->eof = ST_EOM_OK;
1626		else
1627			STps->eof = ST_EOM_ERROR;
1628	}
1629
1630	if (STps->eof == ST_EOM_OK) {
1631		STps->eof = ST_EOD_1;  /* allow next write */
1632		retval = (-ENOSPC);
1633		goto out;
1634	}
1635	else if (STps->eof == ST_EOM_ERROR) {
1636		retval = (-EIO);
1637		goto out;
1638	}
1639
1640	/* Check the buffer readability in cases where copy_user might catch
1641	   the problems after some tape movement. */
1642	if (STp->block_size != 0 &&
1643	    !STbp->do_dio &&
1644	    (copy_from_user(&i, buf, 1) != 0 ||
1645	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1646		retval = (-EFAULT);
1647		goto out;
1648	}
1649
1650	retval = setup_buffering(STp, buf, count, 0);
1651	if (retval)
1652		goto out;
1653
1654	total = count;
1655
1656	memset(cmd, 0, MAX_COMMAND_SIZE);
1657	cmd[0] = WRITE_6;
1658	cmd[1] = (STp->block_size != 0);
1659
1660	STps->rw = ST_WRITING;
1661
1662	b_point = buf;
1663	while (count > 0 && !retry_eot) {
1664
1665		if (STbp->do_dio) {
1666			do_count = count;
1667		}
1668		else {
1669			if (STp->block_size == 0)
1670				do_count = count;
1671			else {
1672				do_count = STbp->buffer_blocks * STp->block_size -
1673					STbp->buffer_bytes;
1674				if (do_count > count)
1675					do_count = count;
1676			}
1677
1678			i = append_to_buffer(b_point, STbp, do_count);
1679			if (i) {
1680				retval = i;
1681				goto out;
1682			}
1683		}
1684		count -= do_count;
1685		b_point += do_count;
1686
1687		async_write = STp->block_size == 0 && !STbp->do_dio &&
1688			STm->do_async_writes && STps->eof < ST_EOM_OK;
1689
1690		if (STp->block_size != 0 && STm->do_buffer_writes &&
1691		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1692		    STbp->buffer_bytes < STbp->buffer_size) {
1693			STp->dirty = 1;
1694			/* Don't write a buffer that is not full enough. */
1695			if (!async_write && count == 0)
1696				break;
1697		}
1698
1699	retry_write:
1700		if (STp->block_size == 0)
1701			blks = transfer = do_count;
1702		else {
1703			if (!STbp->do_dio)
1704				blks = STbp->buffer_bytes;
1705			else
1706				blks = do_count;
1707			blks /= STp->block_size;
1708			transfer = blks * STp->block_size;
1709		}
1710		cmd[2] = blks >> 16;
1711		cmd[3] = blks >> 8;
1712		cmd[4] = blks;
1713
1714		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1715				   STp->device->request_queue->rq_timeout,
1716				   MAX_WRITE_RETRIES, !async_write);
1717		if (!SRpnt) {
1718			retval = STbp->syscall_result;
1719			goto out;
1720		}
1721		if (async_write && !STbp->syscall_result) {
1722			STbp->writing = transfer;
1723			STp->dirty = !(STbp->writing ==
1724				       STbp->buffer_bytes);
1725			SRpnt = NULL;  /* Prevent releasing this request! */
1726			DEB( STp->write_pending = 1; )
1727			break;
1728		}
1729
1730		if (STbp->syscall_result != 0) {
1731			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1732
1733                        DEBC(printk(ST_DEB_MSG "%s: Error on write:\n", name));
1734			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1735				scode = cmdstatp->sense_hdr.sense_key;
1736				if (cmdstatp->remainder_valid)
1737					undone = (int)cmdstatp->uremainder64;
1738				else if (STp->block_size == 0 &&
1739					 scode == VOLUME_OVERFLOW)
1740					undone = transfer;
1741				else
1742					undone = 0;
1743				if (STp->block_size != 0)
1744					undone *= STp->block_size;
1745				if (undone <= do_count) {
1746					/* Only data from this write is not written */
1747					count += undone;
1748					b_point -= undone;
1749					do_count -= undone;
1750					if (STp->block_size)
1751						blks = (transfer - undone) / STp->block_size;
1752					STps->eof = ST_EOM_OK;
1753					/* Continue in fixed block mode if all written
1754					   in this request but still something left to write
1755					   (retval left to zero)
1756					*/
1757					if (STp->block_size == 0 ||
1758					    undone > 0 || count == 0)
1759						retval = (-ENOSPC); /* EOM within current request */
1760                                        DEBC(printk(ST_DEB_MSG
1761                                                       "%s: EOM with %d bytes unwritten.\n",
1762						       name, (int)count));
1763				} else {
1764					/* EOT within data buffered earlier (possible only
1765					   in fixed block mode without direct i/o) */
1766					if (!retry_eot && !cmdstatp->deferred &&
1767					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1768						move_buffer_data(STp->buffer, transfer - undone);
1769						retry_eot = 1;
1770						if (STps->drv_block >= 0) {
1771							STps->drv_block += (transfer - undone) /
1772								STp->block_size;
1773						}
1774						STps->eof = ST_EOM_OK;
1775						DEBC(printk(ST_DEB_MSG
1776							    "%s: Retry write of %d bytes at EOM.\n",
1777							    name, STp->buffer->buffer_bytes));
1778						goto retry_write;
1779					}
1780					else {
1781						/* Either error within data buffered by driver or
1782						   failed retry */
1783						count -= do_count;
1784						blks = do_count = 0;
1785						STps->eof = ST_EOM_ERROR;
1786						STps->drv_block = (-1); /* Too cautious? */
1787						retval = (-EIO);	/* EOM for old data */
1788						DEBC(printk(ST_DEB_MSG
1789							    "%s: EOM with lost data.\n",
1790							    name));
1791					}
1792				}
1793			} else {
1794				count += do_count;
1795				STps->drv_block = (-1);		/* Too cautious? */
1796				retval = STbp->syscall_result;
1797			}
1798
1799		}
1800
1801		if (STps->drv_block >= 0) {
1802			if (STp->block_size == 0)
1803				STps->drv_block += (do_count > 0);
1804			else
1805				STps->drv_block += blks;
1806		}
1807
1808		STbp->buffer_bytes = 0;
1809		STp->dirty = 0;
1810
1811		if (retval || retry_eot) {
1812			if (count < total)
1813				retval = total - count;
1814			goto out;
1815		}
1816	}
1817
1818	if (STps->eof == ST_EOD_1)
1819		STps->eof = ST_EOM_OK;
1820	else if (STps->eof != ST_EOM_OK)
1821		STps->eof = ST_NOEOF;
1822	retval = total - count;
1823
1824 out:
1825	if (SRpnt != NULL)
1826		st_release_request(SRpnt);
1827	release_buffering(STp, 0);
1828	mutex_unlock(&STp->lock);
1829
1830	return retval;
1831}
1832
1833/* Read data from the tape. Returns zero in the normal case, one if the
1834   eof status has changed, and the negative error code in case of a
1835   fatal error. Otherwise updates the buffer and the eof state.
1836
1837   Does release user buffer mapping if it is set.
1838*/
1839static long read_tape(struct scsi_tape *STp, long count,
1840		      struct st_request ** aSRpnt)
1841{
1842	int transfer, blks, bytes;
1843	unsigned char cmd[MAX_COMMAND_SIZE];
1844	struct st_request *SRpnt;
1845	struct st_modedef *STm;
1846	struct st_partstat *STps;
1847	struct st_buffer *STbp;
1848	int retval = 0;
1849	char *name = tape_name(STp);
1850
1851	if (count == 0)
1852		return 0;
1853
1854	STm = &(STp->modes[STp->current_mode]);
1855	STps = &(STp->ps[STp->partition]);
1856	if (STps->eof == ST_FM_HIT)
1857		return 1;
1858	STbp = STp->buffer;
1859
1860	if (STp->block_size == 0)
1861		blks = bytes = count;
1862	else {
1863		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1864			blks = (STp->buffer)->buffer_blocks;
1865			bytes = blks * STp->block_size;
1866		} else {
1867			bytes = count;
1868			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1869				bytes = (STp->buffer)->buffer_size;
1870			blks = bytes / STp->block_size;
1871			bytes = blks * STp->block_size;
1872		}
1873	}
1874
1875	memset(cmd, 0, MAX_COMMAND_SIZE);
1876	cmd[0] = READ_6;
1877	cmd[1] = (STp->block_size != 0);
1878	if (!cmd[1] && STp->sili)
1879		cmd[1] |= 2;
1880	cmd[2] = blks >> 16;
1881	cmd[3] = blks >> 8;
1882	cmd[4] = blks;
1883
1884	SRpnt = *aSRpnt;
1885	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1886			   STp->device->request_queue->rq_timeout,
1887			   MAX_RETRIES, 1);
1888	release_buffering(STp, 1);
1889	*aSRpnt = SRpnt;
1890	if (!SRpnt)
1891		return STbp->syscall_result;
1892
1893	STbp->read_pointer = 0;
1894	STps->at_sm = 0;
1895
1896	/* Something to check */
1897	if (STbp->syscall_result) {
1898		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1899
1900		retval = 1;
1901		DEBC(printk(ST_DEB_MSG "%s: Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1902                            name,
1903                            SRpnt->sense[0], SRpnt->sense[1],
1904                            SRpnt->sense[2], SRpnt->sense[3],
1905                            SRpnt->sense[4], SRpnt->sense[5],
1906                            SRpnt->sense[6], SRpnt->sense[7]));
1907		if (cmdstatp->have_sense) {
1908
1909			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1910				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1911
1912			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1913				/* Compute the residual count */
1914				if (cmdstatp->remainder_valid)
1915					transfer = (int)cmdstatp->uremainder64;
1916				else
1917					transfer = 0;
1918				if (STp->block_size == 0 &&
1919				    cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR)
1920					transfer = bytes;
1921
1922				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1923					if (STp->block_size == 0) {
1924						if (transfer <= 0) {
1925							if (transfer < 0)
1926								printk(KERN_NOTICE
1927								       "%s: Failed to read %d byte block with %d byte transfer.\n",
1928								       name, bytes - transfer, bytes);
1929							if (STps->drv_block >= 0)
1930								STps->drv_block += 1;
1931							STbp->buffer_bytes = 0;
1932							return (-ENOMEM);
1933						}
1934						STbp->buffer_bytes = bytes - transfer;
1935					} else {
1936						st_release_request(SRpnt);
1937						SRpnt = *aSRpnt = NULL;
1938						if (transfer == blks) {	/* We did not get anything, error */
1939							printk(KERN_NOTICE "%s: Incorrect block size.\n", name);
1940							if (STps->drv_block >= 0)
1941								STps->drv_block += blks - transfer + 1;
1942							st_int_ioctl(STp, MTBSR, 1);
1943							return (-EIO);
1944						}
1945						/* We have some data, deliver it */
1946						STbp->buffer_bytes = (blks - transfer) *
1947						    STp->block_size;
1948                                                DEBC(printk(ST_DEB_MSG
1949                                                            "%s: ILI but enough data received %ld %d.\n",
1950                                                            name, count, STbp->buffer_bytes));
1951						if (STps->drv_block >= 0)
1952							STps->drv_block += 1;
1953						if (st_int_ioctl(STp, MTBSR, 1))
1954							return (-EIO);
1955					}
1956				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
1957					if (STps->eof != ST_FM_HIT)
1958						STps->eof = ST_FM_HIT;
1959					else
1960						STps->eof = ST_EOD_2;
1961					if (STp->block_size == 0)
1962						STbp->buffer_bytes = 0;
1963					else
1964						STbp->buffer_bytes =
1965						    bytes - transfer * STp->block_size;
1966                                        DEBC(printk(ST_DEB_MSG
1967                                                    "%s: EOF detected (%d bytes read).\n",
1968                                                    name, STbp->buffer_bytes));
1969				} else if (cmdstatp->flags & SENSE_EOM) {
1970					if (STps->eof == ST_FM)
1971						STps->eof = ST_EOD_1;
1972					else
1973						STps->eof = ST_EOM_OK;
1974					if (STp->block_size == 0)
1975						STbp->buffer_bytes = bytes - transfer;
1976					else
1977						STbp->buffer_bytes =
1978						    bytes - transfer * STp->block_size;
1979
1980                                        DEBC(printk(ST_DEB_MSG "%s: EOM detected (%d bytes read).\n",
1981                                                    name, STbp->buffer_bytes));
1982				}
1983			}
1984			/* end of EOF, EOM, ILI test */
1985			else {	/* nonzero sense key */
1986                                DEBC(printk(ST_DEB_MSG
1987                                            "%s: Tape error while reading.\n", name));
1988				STps->drv_block = (-1);
1989				if (STps->eof == ST_FM &&
1990				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
1991                                        DEBC(printk(ST_DEB_MSG
1992                                                    "%s: Zero returned for first BLANK CHECK after EOF.\n",
1993                                                    name));
1994					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
1995				} else	/* Some other extended sense code */
1996					retval = (-EIO);
1997			}
1998
1999			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2000				STbp->buffer_bytes = 0;
2001		}
2002		/* End of extended sense test */
2003		else {		/* Non-extended sense */
2004			retval = STbp->syscall_result;
2005		}
2006
2007	}
2008	/* End of error handling */
2009	else {			/* Read successful */
2010		STbp->buffer_bytes = bytes;
2011		if (STp->sili) /* In fixed block mode residual is always zero here */
2012			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2013	}
2014
2015	if (STps->drv_block >= 0) {
2016		if (STp->block_size == 0)
2017			STps->drv_block++;
2018		else
2019			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2020	}
2021	return retval;
2022}
2023
2024
2025/* Read command */
2026static ssize_t
2027st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2028{
2029	ssize_t total;
2030	ssize_t retval = 0;
2031	ssize_t i, transfer;
2032	int special, do_dio = 0;
2033	struct st_request *SRpnt = NULL;
2034	struct scsi_tape *STp = filp->private_data;
2035	struct st_modedef *STm;
2036	struct st_partstat *STps;
2037	struct st_buffer *STbp = STp->buffer;
2038	DEB( char *name = tape_name(STp); )
2039
2040	if (mutex_lock_interruptible(&STp->lock))
2041		return -ERESTARTSYS;
2042
2043	retval = rw_checks(STp, filp, count);
2044	if (retval || count == 0)
2045		goto out;
2046
2047	STm = &(STp->modes[STp->current_mode]);
2048	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2049		if (!STm->do_read_ahead) {
2050			retval = (-EINVAL);	/* Read must be integral number of blocks */
2051			goto out;
2052		}
2053		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2054	}
2055
2056	STps = &(STp->ps[STp->partition]);
2057	if (STps->rw == ST_WRITING) {
2058		retval = flush_buffer(STp, 0);
2059		if (retval)
2060			goto out;
2061		STps->rw = ST_READING;
2062	}
2063        DEB(
2064	if (debugging && STps->eof != ST_NOEOF)
2065		printk(ST_DEB_MSG "%s: EOF/EOM flag up (%d). Bytes %d\n", name,
2066		       STps->eof, STbp->buffer_bytes);
2067        ) /* end DEB */
2068
2069	retval = setup_buffering(STp, buf, count, 1);
2070	if (retval)
2071		goto out;
2072	do_dio = STbp->do_dio;
2073
2074	if (STbp->buffer_bytes == 0 &&
2075	    STps->eof >= ST_EOD_1) {
2076		if (STps->eof < ST_EOD) {
2077			STps->eof += 1;
2078			retval = 0;
2079			goto out;
2080		}
2081		retval = (-EIO);	/* EOM or Blank Check */
2082		goto out;
2083	}
2084
2085	if (do_dio) {
2086		/* Check the buffer writability before any tape movement. Don't alter
2087		   buffer data. */
2088		if (copy_from_user(&i, buf, 1) != 0 ||
2089		    copy_to_user(buf, &i, 1) != 0 ||
2090		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2091		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2092			retval = (-EFAULT);
2093			goto out;
2094		}
2095	}
2096
2097	STps->rw = ST_READING;
2098
2099
2100	/* Loop until enough data in buffer or a special condition found */
2101	for (total = 0, special = 0; total < count && !special;) {
2102
2103		/* Get new data if the buffer is empty */
2104		if (STbp->buffer_bytes == 0) {
2105			special = read_tape(STp, count - total, &SRpnt);
2106			if (special < 0) {	/* No need to continue read */
2107				retval = special;
2108				goto out;
2109			}
2110		}
2111
2112		/* Move the data from driver buffer to user buffer */
2113		if (STbp->buffer_bytes > 0) {
2114                        DEB(
2115			if (debugging && STps->eof != ST_NOEOF)
2116				printk(ST_DEB_MSG
2117                                       "%s: EOF up (%d). Left %d, needed %d.\n", name,
2118				       STps->eof, STbp->buffer_bytes,
2119                                       (int)(count - total));
2120                        ) /* end DEB */
2121			transfer = STbp->buffer_bytes < count - total ?
2122			    STbp->buffer_bytes : count - total;
2123			if (!do_dio) {
2124				i = from_buffer(STbp, buf, transfer);
2125				if (i) {
2126					retval = i;
2127					goto out;
2128				}
2129			}
2130			buf += transfer;
2131			total += transfer;
2132		}
2133
2134		if (STp->block_size == 0)
2135			break;	/* Read only one variable length block */
2136
2137	}			/* for (total = 0, special = 0;
2138                                   total < count && !special; ) */
2139
2140	/* Change the eof state if no data from tape or buffer */
2141	if (total == 0) {
2142		if (STps->eof == ST_FM_HIT) {
2143			STps->eof = ST_FM;
2144			STps->drv_block = 0;
2145			if (STps->drv_file >= 0)
2146				STps->drv_file++;
2147		} else if (STps->eof == ST_EOD_1) {
2148			STps->eof = ST_EOD_2;
2149			STps->drv_block = 0;
2150			if (STps->drv_file >= 0)
2151				STps->drv_file++;
2152		} else if (STps->eof == ST_EOD_2)
2153			STps->eof = ST_EOD;
2154	} else if (STps->eof == ST_FM)
2155		STps->eof = ST_NOEOF;
2156	retval = total;
2157
2158 out:
2159	if (SRpnt != NULL) {
2160		st_release_request(SRpnt);
2161		SRpnt = NULL;
2162	}
2163	if (do_dio) {
2164		release_buffering(STp, 1);
2165		STbp->buffer_bytes = 0;
2166	}
2167	mutex_unlock(&STp->lock);
2168
2169	return retval;
2170}
2171
2172
2173
2174DEB(
2175/* Set the driver options */
2176static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm, char *name)
2177{
2178	if (debugging) {
2179		printk(KERN_INFO
2180		       "%s: Mode %d options: buffer writes: %d, async writes: %d, read ahead: %d\n",
2181		       name, STp->current_mode, STm->do_buffer_writes, STm->do_async_writes,
2182		       STm->do_read_ahead);
2183		printk(KERN_INFO
2184		       "%s:    can bsr: %d, two FMs: %d, fast mteom: %d, auto lock: %d,\n",
2185		       name, STp->can_bsr, STp->two_fm, STp->fast_mteom, STp->do_auto_lock);
2186		printk(KERN_INFO
2187		       "%s:    defs for wr: %d, no block limits: %d, partitions: %d, s2 log: %d\n",
2188		       name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions,
2189		       STp->scsi2_logical);
2190		printk(KERN_INFO
2191		       "%s:    sysv: %d nowait: %d sili: %d nowait_filemark: %d\n",
2192		       name, STm->sysv, STp->immediate, STp->sili,
2193		       STp->immediate_filemark);
2194		printk(KERN_INFO "%s:    debugging: %d\n",
2195		       name, debugging);
2196	}
2197}
2198	)
2199
2200
2201static int st_set_options(struct scsi_tape *STp, long options)
2202{
2203	int value;
2204	long code;
2205	struct st_modedef *STm;
2206	char *name = tape_name(STp);
2207	struct cdev *cd0, *cd1;
2208
2209	STm = &(STp->modes[STp->current_mode]);
2210	if (!STm->defined) {
2211		cd0 = STm->cdevs[0]; cd1 = STm->cdevs[1];
2212		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2213		STm->cdevs[0] = cd0; STm->cdevs[1] = cd1;
2214		modes_defined = 1;
2215                DEBC(printk(ST_DEB_MSG
2216                            "%s: Initialized mode %d definition from mode 0\n",
2217                            name, STp->current_mode));
2218	}
2219
2220	code = options & MT_ST_OPTIONS;
2221	if (code == MT_ST_BOOLEANS) {
2222		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2223		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2224		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2225		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2226		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2227		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2228		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2229		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2230		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2231		if ((STp->device)->scsi_level >= SCSI_2)
2232			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2233		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2234		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2235		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2236		STm->sysv = (options & MT_ST_SYSV) != 0;
2237		STp->sili = (options & MT_ST_SILI) != 0;
2238		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2239		     st_log_options(STp, STm, name); )
2240	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2241		value = (code == MT_ST_SETBOOLEANS);
2242		if ((options & MT_ST_BUFFER_WRITES) != 0)
2243			STm->do_buffer_writes = value;
2244		if ((options & MT_ST_ASYNC_WRITES) != 0)
2245			STm->do_async_writes = value;
2246		if ((options & MT_ST_DEF_WRITES) != 0)
2247			STm->defaults_for_writes = value;
2248		if ((options & MT_ST_READ_AHEAD) != 0)
2249			STm->do_read_ahead = value;
2250		if ((options & MT_ST_TWO_FM) != 0)
2251			STp->two_fm = value;
2252		if ((options & MT_ST_FAST_MTEOM) != 0)
2253			STp->fast_mteom = value;
2254		if ((options & MT_ST_AUTO_LOCK) != 0)
2255			STp->do_auto_lock = value;
2256		if ((options & MT_ST_CAN_BSR) != 0)
2257			STp->can_bsr = value;
2258		if ((options & MT_ST_NO_BLKLIMS) != 0)
2259			STp->omit_blklims = value;
2260		if ((STp->device)->scsi_level >= SCSI_2 &&
2261		    (options & MT_ST_CAN_PARTITIONS) != 0)
2262			STp->can_partitions = value;
2263		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2264			STp->scsi2_logical = value;
2265		if ((options & MT_ST_NOWAIT) != 0)
2266			STp->immediate = value;
2267		if ((options & MT_ST_NOWAIT_EOF) != 0)
2268			STp->immediate_filemark = value;
2269		if ((options & MT_ST_SYSV) != 0)
2270			STm->sysv = value;
2271		if ((options & MT_ST_SILI) != 0)
2272			STp->sili = value;
2273                DEB(
2274		if ((options & MT_ST_DEBUGGING) != 0)
2275			debugging = value;
2276			st_log_options(STp, STm, name); )
2277	} else if (code == MT_ST_WRITE_THRESHOLD) {
2278		/* Retained for compatibility */
2279	} else if (code == MT_ST_DEF_BLKSIZE) {
2280		value = (options & ~MT_ST_OPTIONS);
2281		if (value == ~MT_ST_OPTIONS) {
2282			STm->default_blksize = (-1);
2283			DEBC( printk(KERN_INFO "%s: Default block size disabled.\n", name));
2284		} else {
2285			STm->default_blksize = value;
2286			DEBC( printk(KERN_INFO "%s: Default block size set to %d bytes.\n",
2287			       name, STm->default_blksize));
2288			if (STp->ready == ST_READY) {
2289				STp->blksize_changed = 0;
2290				set_mode_densblk(STp, STm);
2291			}
2292		}
2293	} else if (code == MT_ST_TIMEOUTS) {
2294		value = (options & ~MT_ST_OPTIONS);
2295		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2296			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2297			DEBC( printk(KERN_INFO "%s: Long timeout set to %d seconds.\n", name,
2298			       (value & ~MT_ST_SET_LONG_TIMEOUT)));
2299		} else {
2300			blk_queue_rq_timeout(STp->device->request_queue,
2301					     value * HZ);
2302			DEBC( printk(KERN_INFO "%s: Normal timeout set to %d seconds.\n",
2303				name, value) );
2304		}
2305	} else if (code == MT_ST_SET_CLN) {
2306		value = (options & ~MT_ST_OPTIONS) & 0xff;
2307		if (value != 0 &&
2308			(value < EXTENDED_SENSE_START ||
2309				value >= SCSI_SENSE_BUFFERSIZE))
2310			return (-EINVAL);
2311		STp->cln_mode = value;
2312		STp->cln_sense_mask = (options >> 8) & 0xff;
2313		STp->cln_sense_value = (options >> 16) & 0xff;
2314		printk(KERN_INFO
2315		       "%s: Cleaning request mode %d, mask %02x, value %02x\n",
2316		       name, value, STp->cln_sense_mask, STp->cln_sense_value);
2317	} else if (code == MT_ST_DEF_OPTIONS) {
2318		code = (options & ~MT_ST_CLEAR_DEFAULT);
2319		value = (options & MT_ST_CLEAR_DEFAULT);
2320		if (code == MT_ST_DEF_DENSITY) {
2321			if (value == MT_ST_CLEAR_DEFAULT) {
2322				STm->default_density = (-1);
2323				DEBC( printk(KERN_INFO "%s: Density default disabled.\n",
2324                                       name));
2325			} else {
2326				STm->default_density = value & 0xff;
2327				DEBC( printk(KERN_INFO "%s: Density default set to %x\n",
2328				       name, STm->default_density));
2329				if (STp->ready == ST_READY) {
2330					STp->density_changed = 0;
2331					set_mode_densblk(STp, STm);
2332				}
2333			}
2334		} else if (code == MT_ST_DEF_DRVBUFFER) {
2335			if (value == MT_ST_CLEAR_DEFAULT) {
2336				STp->default_drvbuffer = 0xff;
2337				DEBC( printk(KERN_INFO
2338                                       "%s: Drive buffer default disabled.\n", name));
2339			} else {
2340				STp->default_drvbuffer = value & 7;
2341				DEBC( printk(KERN_INFO
2342                                       "%s: Drive buffer default set to %x\n",
2343				       name, STp->default_drvbuffer));
2344				if (STp->ready == ST_READY)
2345					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2346			}
2347		} else if (code == MT_ST_DEF_COMPRESSION) {
2348			if (value == MT_ST_CLEAR_DEFAULT) {
2349				STm->default_compression = ST_DONT_TOUCH;
2350				DEBC( printk(KERN_INFO
2351                                       "%s: Compression default disabled.\n", name));
2352			} else {
2353				if ((value & 0xff00) != 0) {
2354					STp->c_algo = (value & 0xff00) >> 8;
2355					DEBC( printk(KERN_INFO "%s: Compression algorithm set to 0x%x.\n",
2356					       name, STp->c_algo));
2357				}
2358				if ((value & 0xff) != 0xff) {
2359					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2360					DEBC( printk(KERN_INFO "%s: Compression default set to %x\n",
2361					       name, (value & 1)));
2362					if (STp->ready == ST_READY) {
2363						STp->compression_changed = 0;
2364						st_compression(STp, (STm->default_compression == ST_YES));
2365					}
2366				}
2367			}
2368		}
2369	} else
2370		return (-EIO);
2371
2372	return 0;
2373}
2374
2375#define MODE_HEADER_LENGTH  4
2376
2377/* Mode header and page byte offsets */
2378#define MH_OFF_DATA_LENGTH     0
2379#define MH_OFF_MEDIUM_TYPE     1
2380#define MH_OFF_DEV_SPECIFIC    2
2381#define MH_OFF_BDESCS_LENGTH   3
2382#define MP_OFF_PAGE_NBR        0
2383#define MP_OFF_PAGE_LENGTH     1
2384
2385/* Mode header and page bit masks */
2386#define MH_BIT_WP              0x80
2387#define MP_MSK_PAGE_NBR        0x3f
2388
2389/* Don't return block descriptors */
2390#define MODE_SENSE_OMIT_BDESCS 0x08
2391
2392#define MODE_SELECT_PAGE_FORMAT 0x10
2393
2394/* Read a mode page into the tape buffer. The block descriptors are included
2395   if incl_block_descs is true. The page control is ored to the page number
2396   parameter, if necessary. */
2397static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2398{
2399	unsigned char cmd[MAX_COMMAND_SIZE];
2400	struct st_request *SRpnt;
2401
2402	memset(cmd, 0, MAX_COMMAND_SIZE);
2403	cmd[0] = MODE_SENSE;
2404	if (omit_block_descs)
2405		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2406	cmd[2] = page;
2407	cmd[4] = 255;
2408
2409	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2410			   STp->device->request_queue->rq_timeout, 0, 1);
2411	if (SRpnt == NULL)
2412		return (STp->buffer)->syscall_result;
2413
2414	st_release_request(SRpnt);
2415
2416	return STp->buffer->syscall_result;
2417}
2418
2419
2420/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2421   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2422static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2423{
2424	int pgo;
2425	unsigned char cmd[MAX_COMMAND_SIZE];
2426	struct st_request *SRpnt;
2427	int timeout;
2428
2429	memset(cmd, 0, MAX_COMMAND_SIZE);
2430	cmd[0] = MODE_SELECT;
2431	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2432	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2433	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2434
2435	/* Clear reserved fields */
2436	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2437	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2438	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2439	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2440
2441	timeout = slow ?
2442		STp->long_timeout : STp->device->request_queue->rq_timeout;
2443	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2444			   timeout, 0, 1);
2445	if (SRpnt == NULL)
2446		return (STp->buffer)->syscall_result;
2447
2448	st_release_request(SRpnt);
2449
2450	return STp->buffer->syscall_result;
2451}
2452
2453
2454#define COMPRESSION_PAGE        0x0f
2455#define COMPRESSION_PAGE_LENGTH 16
2456
2457#define CP_OFF_DCE_DCC          2
2458#define CP_OFF_C_ALGO           7
2459
2460#define DCE_MASK  0x80
2461#define DCC_MASK  0x40
2462#define RED_MASK  0x60
2463
2464
2465/* Control the compression with mode page 15. Algorithm not changed if zero.
2466
2467   The block descriptors are read and written because Sony SDT-7000 does not
2468   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2469   Including block descriptors should not cause any harm to other drives. */
2470
2471static int st_compression(struct scsi_tape * STp, int state)
2472{
2473	int retval;
2474	int mpoffs;  /* Offset to mode page start */
2475	unsigned char *b_data = (STp->buffer)->b_data;
2476	DEB( char *name = tape_name(STp); )
2477
2478	if (STp->ready != ST_READY)
2479		return (-EIO);
2480
2481	/* Read the current page contents */
2482	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2483	if (retval) {
2484                DEBC(printk(ST_DEB_MSG "%s: Compression mode page not supported.\n",
2485                            name));
2486		return (-EIO);
2487	}
2488
2489	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2490        DEBC(printk(ST_DEB_MSG "%s: Compression state is %d.\n", name,
2491                    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0)));
2492
2493	/* Check if compression can be changed */
2494	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2495                DEBC(printk(ST_DEB_MSG "%s: Compression not supported.\n", name));
2496		return (-EIO);
2497	}
2498
2499	/* Do the change */
2500	if (state) {
2501		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2502		if (STp->c_algo != 0)
2503			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2504	}
2505	else {
2506		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2507		if (STp->c_algo != 0)
2508			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2509	}
2510
2511	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2512	if (retval) {
2513                DEBC(printk(ST_DEB_MSG "%s: Compression change failed.\n", name));
2514		return (-EIO);
2515	}
2516        DEBC(printk(ST_DEB_MSG "%s: Compression state changed to %d.\n",
2517		       name, state));
2518
2519	STp->compression_changed = 1;
2520	return 0;
2521}
2522
2523
2524/* Process the load and unload commands (does unload if the load code is zero) */
2525static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2526{
2527	int retval = (-EIO), timeout;
2528	DEB( char *name = tape_name(STp); )
2529	unsigned char cmd[MAX_COMMAND_SIZE];
2530	struct st_partstat *STps;
2531	struct st_request *SRpnt;
2532
2533	if (STp->ready != ST_READY && !load_code) {
2534		if (STp->ready == ST_NO_TAPE)
2535			return (-ENOMEDIUM);
2536		else
2537			return (-EIO);
2538	}
2539
2540	memset(cmd, 0, MAX_COMMAND_SIZE);
2541	cmd[0] = START_STOP;
2542	if (load_code)
2543		cmd[4] |= 1;
2544	/*
2545	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2546	 */
2547	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2548	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2549		DEBC(printk(ST_DEB_MSG "%s: Enhanced %sload slot %2d.\n",
2550			    name, (cmd[4]) ? "" : "un",
2551			    load_code - MT_ST_HPLOADER_OFFSET));
2552		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2553	}
2554	if (STp->immediate) {
2555		cmd[1] = 1;	/* Don't wait for completion */
2556		timeout = STp->device->request_queue->rq_timeout;
2557	}
2558	else
2559		timeout = STp->long_timeout;
2560
2561	DEBC(
2562		if (!load_code)
2563		printk(ST_DEB_MSG "%s: Unloading tape.\n", name);
2564		else
2565		printk(ST_DEB_MSG "%s: Loading tape.\n", name);
2566		);
2567
2568	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2569			   timeout, MAX_RETRIES, 1);
2570	if (!SRpnt)
2571		return (STp->buffer)->syscall_result;
2572
2573	retval = (STp->buffer)->syscall_result;
2574	st_release_request(SRpnt);
2575
2576	if (!retval) {	/* SCSI command successful */
2577
2578		if (!load_code) {
2579			STp->rew_at_close = 0;
2580			STp->ready = ST_NO_TAPE;
2581		}
2582		else {
2583			STp->rew_at_close = STp->autorew_dev;
2584			retval = check_tape(STp, filp);
2585			if (retval > 0)
2586				retval = 0;
2587		}
2588	}
2589	else {
2590		STps = &(STp->ps[STp->partition]);
2591		STps->drv_file = STps->drv_block = (-1);
2592	}
2593
2594	return retval;
2595}
2596
2597#if DEBUG
2598#define ST_DEB_FORWARD  0
2599#define ST_DEB_BACKWARD 1
2600static void deb_space_print(char *name, int direction, char *units, unsigned char *cmd)
2601{
2602	s32 sc;
2603
2604	sc = cmd[2] & 0x80 ? 0xff000000 : 0;
2605	sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2606	if (direction)
2607		sc = -sc;
2608	printk(ST_DEB_MSG "%s: Spacing tape %s over %d %s.\n", name,
2609	       direction ? "backward" : "forward", sc, units);
2610}
2611#endif
2612
2613
2614/* Internal ioctl function */
2615static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2616{
2617	int timeout;
2618	long ltmp;
2619	int ioctl_result;
2620	int chg_eof = 1;
2621	unsigned char cmd[MAX_COMMAND_SIZE];
2622	struct st_request *SRpnt;
2623	struct st_partstat *STps;
2624	int fileno, blkno, at_sm, undone;
2625	int datalen = 0, direction = DMA_NONE;
2626	char *name = tape_name(STp);
2627
2628	WARN_ON(STp->buffer->do_dio != 0);
2629	if (STp->ready != ST_READY) {
2630		if (STp->ready == ST_NO_TAPE)
2631			return (-ENOMEDIUM);
2632		else
2633			return (-EIO);
2634	}
2635	timeout = STp->long_timeout;
2636	STps = &(STp->ps[STp->partition]);
2637	fileno = STps->drv_file;
2638	blkno = STps->drv_block;
2639	at_sm = STps->at_sm;
2640
2641	memset(cmd, 0, MAX_COMMAND_SIZE);
2642	switch (cmd_in) {
2643	case MTFSFM:
2644		chg_eof = 0;	/* Changed from the FSF after this */
2645	case MTFSF:
2646		cmd[0] = SPACE;
2647		cmd[1] = 0x01;	/* Space FileMarks */
2648		cmd[2] = (arg >> 16);
2649		cmd[3] = (arg >> 8);
2650		cmd[4] = arg;
2651                DEBC(deb_space_print(name, ST_DEB_FORWARD, "filemarks", cmd);)
2652		if (fileno >= 0)
2653			fileno += arg;
2654		blkno = 0;
2655		at_sm &= (arg == 0);
2656		break;
2657	case MTBSFM:
2658		chg_eof = 0;	/* Changed from the FSF after this */
2659	case MTBSF:
2660		cmd[0] = SPACE;
2661		cmd[1] = 0x01;	/* Space FileMarks */
2662		ltmp = (-arg);
2663		cmd[2] = (ltmp >> 16);
2664		cmd[3] = (ltmp >> 8);
2665		cmd[4] = ltmp;
2666                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "filemarks", cmd);)
2667		if (fileno >= 0)
2668			fileno -= arg;
2669		blkno = (-1);	/* We can't know the block number */
2670		at_sm &= (arg == 0);
2671		break;
2672	case MTFSR:
2673		cmd[0] = SPACE;
2674		cmd[1] = 0x00;	/* Space Blocks */
2675		cmd[2] = (arg >> 16);
2676		cmd[3] = (arg >> 8);
2677		cmd[4] = arg;
2678                DEBC(deb_space_print(name, ST_DEB_FORWARD, "blocks", cmd);)
2679		if (blkno >= 0)
2680			blkno += arg;
2681		at_sm &= (arg == 0);
2682		break;
2683	case MTBSR:
2684		cmd[0] = SPACE;
2685		cmd[1] = 0x00;	/* Space Blocks */
2686		ltmp = (-arg);
2687		cmd[2] = (ltmp >> 16);
2688		cmd[3] = (ltmp >> 8);
2689		cmd[4] = ltmp;
2690                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "blocks", cmd);)
2691		if (blkno >= 0)
2692			blkno -= arg;
2693		at_sm &= (arg == 0);
2694		break;
2695	case MTFSS:
2696		cmd[0] = SPACE;
2697		cmd[1] = 0x04;	/* Space Setmarks */
2698		cmd[2] = (arg >> 16);
2699		cmd[3] = (arg >> 8);
2700		cmd[4] = arg;
2701                DEBC(deb_space_print(name, ST_DEB_FORWARD, "setmarks", cmd);)
2702		if (arg != 0) {
2703			blkno = fileno = (-1);
2704			at_sm = 1;
2705		}
2706		break;
2707	case MTBSS:
2708		cmd[0] = SPACE;
2709		cmd[1] = 0x04;	/* Space Setmarks */
2710		ltmp = (-arg);
2711		cmd[2] = (ltmp >> 16);
2712		cmd[3] = (ltmp >> 8);
2713		cmd[4] = ltmp;
2714                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "setmarks", cmd);)
2715		if (arg != 0) {
2716			blkno = fileno = (-1);
2717			at_sm = 1;
2718		}
2719		break;
2720	case MTWEOF:
2721	case MTWEOFI:
2722	case MTWSM:
2723		if (STp->write_prot)
2724			return (-EACCES);
2725		cmd[0] = WRITE_FILEMARKS;
2726		if (cmd_in == MTWSM)
2727			cmd[1] = 2;
2728		if (cmd_in == MTWEOFI ||
2729		    (cmd_in == MTWEOF && STp->immediate_filemark))
2730			cmd[1] |= 1;
2731		cmd[2] = (arg >> 16);
2732		cmd[3] = (arg >> 8);
2733		cmd[4] = arg;
2734		timeout = STp->device->request_queue->rq_timeout;
2735                DEBC(
2736		     if (cmd_in != MTWSM)
2737                               printk(ST_DEB_MSG "%s: Writing %d filemarks.\n", name,
2738				 cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
2739                     else
2740				printk(ST_DEB_MSG "%s: Writing %d setmarks.\n", name,
2741				 cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
2742		)
2743		if (fileno >= 0)
2744			fileno += arg;
2745		blkno = 0;
2746		at_sm = (cmd_in == MTWSM);
2747		break;
2748	case MTREW:
2749		cmd[0] = REZERO_UNIT;
2750		if (STp->immediate) {
2751			cmd[1] = 1;	/* Don't wait for completion */
2752			timeout = STp->device->request_queue->rq_timeout;
2753		}
2754                DEBC(printk(ST_DEB_MSG "%s: Rewinding tape.\n", name));
2755		fileno = blkno = at_sm = 0;
2756		break;
2757	case MTNOP:
2758                DEBC(printk(ST_DEB_MSG "%s: No op on tape.\n", name));
2759		return 0;	/* Should do something ? */
2760		break;
2761	case MTRETEN:
2762		cmd[0] = START_STOP;
2763		if (STp->immediate) {
2764			cmd[1] = 1;	/* Don't wait for completion */
2765			timeout = STp->device->request_queue->rq_timeout;
2766		}
2767		cmd[4] = 3;
2768                DEBC(printk(ST_DEB_MSG "%s: Retensioning tape.\n", name));
2769		fileno = blkno = at_sm = 0;
2770		break;
2771	case MTEOM:
2772		if (!STp->fast_mteom) {
2773			/* space to the end of tape */
2774			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2775			fileno = STps->drv_file;
2776			if (STps->eof >= ST_EOD_1)
2777				return 0;
2778			/* The next lines would hide the number of spaced FileMarks
2779			   That's why I inserted the previous lines. I had no luck
2780			   with detecting EOM with FSF, so we go now to EOM.
2781			   Joerg Weule */
2782		} else
2783			fileno = (-1);
2784		cmd[0] = SPACE;
2785		cmd[1] = 3;
2786                DEBC(printk(ST_DEB_MSG "%s: Spacing to end of recorded medium.\n",
2787                            name));
2788		blkno = -1;
2789		at_sm = 0;
2790		break;
2791	case MTERASE:
2792		if (STp->write_prot)
2793			return (-EACCES);
2794		cmd[0] = ERASE;
2795		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2796		if (STp->immediate) {
2797			cmd[1] |= 2;	/* Don't wait for completion */
2798			timeout = STp->device->request_queue->rq_timeout;
2799		}
2800		else
2801			timeout = STp->long_timeout * 8;
2802
2803                DEBC(printk(ST_DEB_MSG "%s: Erasing tape.\n", name));
2804		fileno = blkno = at_sm = 0;
2805		break;
2806	case MTSETBLK:		/* Set block length */
2807	case MTSETDENSITY:	/* Set tape density */
2808	case MTSETDRVBUFFER:	/* Set drive buffering */
2809	case SET_DENS_AND_BLK:	/* Set density and block size */
2810		chg_eof = 0;
2811		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2812			return (-EIO);	/* Not allowed if data in buffer */
2813		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2814		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2815		    STp->max_block > 0 &&
2816		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2817		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2818			printk(KERN_WARNING "%s: Illegal block size.\n", name);
2819			return (-EINVAL);
2820		}
2821		cmd[0] = MODE_SELECT;
2822		if ((STp->use_pf & USE_PF))
2823			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2824		cmd[4] = datalen = 12;
2825		direction = DMA_TO_DEVICE;
2826
2827		memset((STp->buffer)->b_data, 0, 12);
2828		if (cmd_in == MTSETDRVBUFFER)
2829			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2830		else
2831			(STp->buffer)->b_data[2] =
2832			    STp->drv_buffer << 4;
2833		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2834		if (cmd_in == MTSETDENSITY) {
2835			(STp->buffer)->b_data[4] = arg;
2836			STp->density_changed = 1;	/* At least we tried ;-) */
2837		} else if (cmd_in == SET_DENS_AND_BLK)
2838			(STp->buffer)->b_data[4] = arg >> 24;
2839		else
2840			(STp->buffer)->b_data[4] = STp->density;
2841		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2842			ltmp = arg & MT_ST_BLKSIZE_MASK;
2843			if (cmd_in == MTSETBLK)
2844				STp->blksize_changed = 1; /* At least we tried ;-) */
2845		} else
2846			ltmp = STp->block_size;
2847		(STp->buffer)->b_data[9] = (ltmp >> 16);
2848		(STp->buffer)->b_data[10] = (ltmp >> 8);
2849		(STp->buffer)->b_data[11] = ltmp;
2850		timeout = STp->device->request_queue->rq_timeout;
2851                DEBC(
2852			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2853				printk(ST_DEB_MSG
2854                                       "%s: Setting block size to %d bytes.\n", name,
2855				       (STp->buffer)->b_data[9] * 65536 +
2856				       (STp->buffer)->b_data[10] * 256 +
2857				       (STp->buffer)->b_data[11]);
2858			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2859				printk(ST_DEB_MSG
2860                                       "%s: Setting density code to %x.\n", name,
2861				       (STp->buffer)->b_data[4]);
2862			if (cmd_in == MTSETDRVBUFFER)
2863				printk(ST_DEB_MSG
2864                                       "%s: Setting drive buffer code to %d.\n", name,
2865				    ((STp->buffer)->b_data[2] >> 4) & 7);
2866		)
2867		break;
2868	default:
2869		return (-ENOSYS);
2870	}
2871
2872	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2873			   timeout, MAX_RETRIES, 1);
2874	if (!SRpnt)
2875		return (STp->buffer)->syscall_result;
2876
2877	ioctl_result = (STp->buffer)->syscall_result;
2878
2879	if (!ioctl_result) {	/* SCSI command successful */
2880		st_release_request(SRpnt);
2881		SRpnt = NULL;
2882		STps->drv_block = blkno;
2883		STps->drv_file = fileno;
2884		STps->at_sm = at_sm;
2885
2886		if (cmd_in == MTBSFM)
2887			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2888		else if (cmd_in == MTFSFM)
2889			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2890
2891		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2892			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2893			if (STp->block_size != 0) {
2894				(STp->buffer)->buffer_blocks =
2895				    (STp->buffer)->buffer_size / STp->block_size;
2896			}
2897			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2898			if (cmd_in == SET_DENS_AND_BLK)
2899				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2900		} else if (cmd_in == MTSETDRVBUFFER)
2901			STp->drv_buffer = (arg & 7);
2902		else if (cmd_in == MTSETDENSITY)
2903			STp->density = arg;
2904
2905		if (cmd_in == MTEOM)
2906			STps->eof = ST_EOD;
2907		else if (cmd_in == MTFSF)
2908			STps->eof = ST_FM;
2909		else if (chg_eof)
2910			STps->eof = ST_NOEOF;
2911
2912		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
2913			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
2914	} else { /* SCSI command was not completely successful. Don't return
2915                    from this block without releasing the SCSI command block! */
2916		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
2917
2918		if (cmdstatp->flags & SENSE_EOM) {
2919			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
2920			    cmd_in != MTBSR && cmd_in != MTBSS)
2921				STps->eof = ST_EOM_OK;
2922			STps->drv_block = 0;
2923		}
2924
2925		if (cmdstatp->remainder_valid)
2926			undone = (int)cmdstatp->uremainder64;
2927		else
2928			undone = 0;
2929
2930		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
2931		    cmdstatp->have_sense &&
2932		    (cmdstatp->flags & SENSE_EOM)) {
2933			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
2934			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
2935				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
2936				STps->eof = ST_NOEOF;
2937			} else {  /* Writing EOF(s) failed */
2938				if (fileno >= 0)
2939					fileno -= undone;
2940				if (undone < arg)
2941					STps->eof = ST_NOEOF;
2942			}
2943			STps->drv_file = fileno;
2944		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
2945			if (fileno >= 0)
2946				STps->drv_file = fileno - undone;
2947			else
2948				STps->drv_file = fileno;
2949			STps->drv_block = -1;
2950			STps->eof = ST_NOEOF;
2951		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
2952			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
2953				undone = (-undone);
2954			if (STps->drv_file >= 0)
2955				STps->drv_file = fileno + undone;
2956			STps->drv_block = 0;
2957			STps->eof = ST_NOEOF;
2958		} else if (cmd_in == MTFSR) {
2959			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
2960				if (STps->drv_file >= 0)
2961					STps->drv_file++;
2962				STps->drv_block = 0;
2963				STps->eof = ST_FM;
2964			} else {
2965				if (blkno >= undone)
2966					STps->drv_block = blkno - undone;
2967				else
2968					STps->drv_block = (-1);
2969				STps->eof = ST_NOEOF;
2970			}
2971		} else if (cmd_in == MTBSR) {
2972			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
2973				STps->drv_file--;
2974				STps->drv_block = (-1);
2975			} else {
2976				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
2977					undone = (-undone);
2978				if (STps->drv_block >= 0)
2979					STps->drv_block = blkno + undone;
2980			}
2981			STps->eof = ST_NOEOF;
2982		} else if (cmd_in == MTEOM) {
2983			STps->drv_file = (-1);
2984			STps->drv_block = (-1);
2985			STps->eof = ST_EOD;
2986		} else if (cmd_in == MTSETBLK ||
2987			   cmd_in == MTSETDENSITY ||
2988			   cmd_in == MTSETDRVBUFFER ||
2989			   cmd_in == SET_DENS_AND_BLK) {
2990			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
2991			    !(STp->use_pf & PF_TESTED)) {
2992				/* Try the other possible state of Page Format if not
2993				   already tried */
2994				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
2995				st_release_request(SRpnt);
2996				SRpnt = NULL;
2997				return st_int_ioctl(STp, cmd_in, arg);
2998			}
2999		} else if (chg_eof)
3000			STps->eof = ST_NOEOF;
3001
3002		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3003			STps->eof = ST_EOD;
3004
3005		st_release_request(SRpnt);
3006		SRpnt = NULL;
3007	}
3008
3009	return ioctl_result;
3010}
3011
3012
3013/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3014   structure. */
3015
3016static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3017			int logical)
3018{
3019	int result;
3020	unsigned char scmd[MAX_COMMAND_SIZE];
3021	struct st_request *SRpnt;
3022	DEB( char *name = tape_name(STp); )
3023
3024	if (STp->ready != ST_READY)
3025		return (-EIO);
3026
3027	memset(scmd, 0, MAX_COMMAND_SIZE);
3028	if ((STp->device)->scsi_level < SCSI_2) {
3029		scmd[0] = QFA_REQUEST_BLOCK;
3030		scmd[4] = 3;
3031	} else {
3032		scmd[0] = READ_POSITION;
3033		if (!logical && !STp->scsi2_logical)
3034			scmd[1] = 1;
3035	}
3036	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3037			   STp->device->request_queue->rq_timeout,
3038			   MAX_READY_RETRIES, 1);
3039	if (!SRpnt)
3040		return (STp->buffer)->syscall_result;
3041
3042	if ((STp->buffer)->syscall_result != 0 ||
3043	    (STp->device->scsi_level >= SCSI_2 &&
3044	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3045		*block = *partition = 0;
3046                DEBC(printk(ST_DEB_MSG "%s: Can't read tape position.\n", name));
3047		result = (-EIO);
3048	} else {
3049		result = 0;
3050		if ((STp->device)->scsi_level < SCSI_2) {
3051			*block = ((STp->buffer)->b_data[0] << 16)
3052			    + ((STp->buffer)->b_data[1] << 8)
3053			    + (STp->buffer)->b_data[2];
3054			*partition = 0;
3055		} else {
3056			*block = ((STp->buffer)->b_data[4] << 24)
3057			    + ((STp->buffer)->b_data[5] << 16)
3058			    + ((STp->buffer)->b_data[6] << 8)
3059			    + (STp->buffer)->b_data[7];
3060			*partition = (STp->buffer)->b_data[1];
3061			if (((STp->buffer)->b_data[0] & 0x80) &&
3062			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3063				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3064		}
3065                DEBC(printk(ST_DEB_MSG "%s: Got tape pos. blk %d part %d.\n", name,
3066                            *block, *partition));
3067	}
3068	st_release_request(SRpnt);
3069	SRpnt = NULL;
3070
3071	return result;
3072}
3073
3074
3075/* Set the tape block and partition. Negative partition means that only the
3076   block should be set in vendor specific way. */
3077static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3078			int logical)
3079{
3080	struct st_partstat *STps;
3081	int result, p;
3082	unsigned int blk;
3083	int timeout;
3084	unsigned char scmd[MAX_COMMAND_SIZE];
3085	struct st_request *SRpnt;
3086	DEB( char *name = tape_name(STp); )
3087
3088	if (STp->ready != ST_READY)
3089		return (-EIO);
3090	timeout = STp->long_timeout;
3091	STps = &(STp->ps[STp->partition]);
3092
3093        DEBC(printk(ST_DEB_MSG "%s: Setting block to %d and partition to %d.\n",
3094                    name, block, partition));
3095	DEB(if (partition < 0)
3096		return (-EIO); )
3097
3098	/* Update the location at the partition we are leaving */
3099	if ((!STp->can_partitions && partition != 0) ||
3100	    partition >= ST_NBR_PARTITIONS)
3101		return (-EINVAL);
3102	if (partition != STp->partition) {
3103		if (get_location(STp, &blk, &p, 1))
3104			STps->last_block_valid = 0;
3105		else {
3106			STps->last_block_valid = 1;
3107			STps->last_block_visited = blk;
3108                        DEBC(printk(ST_DEB_MSG
3109                                    "%s: Visited block %d for partition %d saved.\n",
3110                                    name, blk, STp->partition));
3111		}
3112	}
3113
3114	memset(scmd, 0, MAX_COMMAND_SIZE);
3115	if ((STp->device)->scsi_level < SCSI_2) {
3116		scmd[0] = QFA_SEEK_BLOCK;
3117		scmd[2] = (block >> 16);
3118		scmd[3] = (block >> 8);
3119		scmd[4] = block;
3120		scmd[5] = 0;
3121	} else {
3122		scmd[0] = SEEK_10;
3123		scmd[3] = (block >> 24);
3124		scmd[4] = (block >> 16);
3125		scmd[5] = (block >> 8);
3126		scmd[6] = block;
3127		if (!logical && !STp->scsi2_logical)
3128			scmd[1] = 4;
3129		if (STp->partition != partition) {
3130			scmd[1] |= 2;
3131			scmd[8] = partition;
3132                        DEBC(printk(ST_DEB_MSG
3133                                    "%s: Trying to change partition from %d to %d\n",
3134                                    name, STp->partition, partition));
3135		}
3136	}
3137	if (STp->immediate) {
3138		scmd[1] |= 1;		/* Don't wait for completion */
3139		timeout = STp->device->request_queue->rq_timeout;
3140	}
3141
3142	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3143			   timeout, MAX_READY_RETRIES, 1);
3144	if (!SRpnt)
3145		return (STp->buffer)->syscall_result;
3146
3147	STps->drv_block = STps->drv_file = (-1);
3148	STps->eof = ST_NOEOF;
3149	if ((STp->buffer)->syscall_result != 0) {
3150		result = (-EIO);
3151		if (STp->can_partitions &&
3152		    (STp->device)->scsi_level >= SCSI_2 &&
3153		    (p = find_partition(STp)) >= 0)
3154			STp->partition = p;
3155	} else {
3156		if (STp->can_partitions) {
3157			STp->partition = partition;
3158			STps = &(STp->ps[partition]);
3159			if (!STps->last_block_valid ||
3160			    STps->last_block_visited != block) {
3161				STps->at_sm = 0;
3162				STps->rw = ST_IDLE;
3163			}
3164		} else
3165			STps->at_sm = 0;
3166		if (block == 0)
3167			STps->drv_block = STps->drv_file = 0;
3168		result = 0;
3169	}
3170
3171	st_release_request(SRpnt);
3172	SRpnt = NULL;
3173
3174	return result;
3175}
3176
3177
3178/* Find the current partition number for the drive status. Called from open and
3179   returns either partition number of negative error code. */
3180static int find_partition(struct scsi_tape *STp)
3181{
3182	int i, partition;
3183	unsigned int block;
3184
3185	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3186		return i;
3187	if (partition >= ST_NBR_PARTITIONS)
3188		return (-EIO);
3189	return partition;
3190}
3191
3192
3193/* Change the partition if necessary */
3194static int switch_partition(struct scsi_tape *STp)
3195{
3196	struct st_partstat *STps;
3197
3198	if (STp->partition == STp->new_partition)
3199		return 0;
3200	STps = &(STp->ps[STp->new_partition]);
3201	if (!STps->last_block_valid)
3202		STps->last_block_visited = 0;
3203	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3204}
3205
3206/* Functions for reading and writing the medium partition mode page. */
3207
3208#define PART_PAGE   0x11
3209#define PART_PAGE_FIXED_LENGTH 8
3210
3211#define PP_OFF_MAX_ADD_PARTS   2
3212#define PP_OFF_NBR_ADD_PARTS   3
3213#define PP_OFF_FLAGS           4
3214#define PP_OFF_PART_UNITS      6
3215#define PP_OFF_RESERVED        7
3216
3217#define PP_BIT_IDP             0x20
3218#define PP_MSK_PSUM_MB         0x10
3219
3220/* Get the number of partitions on the tape. As a side effect reads the
3221   mode page into the tape buffer. */
3222static int nbr_partitions(struct scsi_tape *STp)
3223{
3224	int result;
3225	DEB( char *name = tape_name(STp); )
3226
3227	if (STp->ready != ST_READY)
3228		return (-EIO);
3229
3230	result = read_mode_page(STp, PART_PAGE, 1);
3231
3232	if (result) {
3233                DEBC(printk(ST_DEB_MSG "%s: Can't read medium partition page.\n",
3234                            name));
3235		result = (-EIO);
3236	} else {
3237		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3238					      PP_OFF_NBR_ADD_PARTS] + 1;
3239                DEBC(printk(ST_DEB_MSG "%s: Number of partitions %d.\n", name, result));
3240	}
3241
3242	return result;
3243}
3244
3245
3246/* Partition the tape into two partitions if size > 0 or one partition if
3247   size == 0.
3248
3249   The block descriptors are read and written because Sony SDT-7000 does not
3250   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3251
3252   My HP C1533A drive returns only one partition size field. This is used to
3253   set the size of partition 1. There is no size field for the default partition.
3254   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3255   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3256   The following algorithm is used to accommodate both drives: if the number of
3257   partition size fields is greater than the maximum number of additional partitions
3258   in the mode page, the second field is used. Otherwise the first field is used.
3259
3260   For Seagate DDS drives the page length must be 8 when no partitions is defined
3261   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3262   is acceptable also to some other old drives and enforced if the first partition
3263   size field is used for the first additional partition size.
3264 */
3265static int partition_tape(struct scsi_tape *STp, int size)
3266{
3267	char *name = tape_name(STp);
3268	int result;
3269	int pgo, psd_cnt, psdo;
3270	unsigned char *bp;
3271
3272	result = read_mode_page(STp, PART_PAGE, 0);
3273	if (result) {
3274		DEBC(printk(ST_DEB_MSG "%s: Can't read partition mode page.\n", name));
3275		return result;
3276	}
3277	/* The mode page is in the buffer. Let's modify it and write it. */
3278	bp = (STp->buffer)->b_data;
3279	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3280	DEBC(printk(ST_DEB_MSG "%s: Partition page length is %d bytes.\n",
3281		    name, bp[pgo + MP_OFF_PAGE_LENGTH] + 2));
3282
3283	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3284	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3285	if (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS]) {
3286		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest of the tape */
3287		psdo += 2;
3288	}
3289	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3290
3291	DEBC(printk("%s: psd_cnt %d, max.parts %d, nbr_parts %d\n", name,
3292		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3293		    bp[pgo + PP_OFF_NBR_ADD_PARTS]));
3294
3295	if (size <= 0) {
3296		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3297		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3298		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3299                DEBC(printk(ST_DEB_MSG "%s: Formatting tape with one partition.\n",
3300                            name));
3301	} else {
3302		bp[psdo] = (size >> 8) & 0xff;
3303		bp[psdo + 1] = size & 0xff;
3304		bp[pgo + 3] = 1;
3305		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3306		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3307                DEBC(printk(ST_DEB_MSG
3308                            "%s: Formatting tape with two partitions (1 = %d MB).\n",
3309                            name, size));
3310	}
3311	bp[pgo + PP_OFF_PART_UNITS] = 0;
3312	bp[pgo + PP_OFF_RESERVED] = 0;
3313	bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | PP_MSK_PSUM_MB;
3314
3315	result = write_mode_page(STp, PART_PAGE, 1);
3316	if (result) {
3317		printk(KERN_INFO "%s: Partitioning of tape failed.\n", name);
3318		result = (-EIO);
3319	}
3320
3321	return result;
3322}
3323
3324
3325
3326/* The ioctl command */
3327static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3328{
3329	int i, cmd_nr, cmd_type, bt;
3330	int retval = 0;
3331	unsigned int blk;
3332	struct scsi_tape *STp = file->private_data;
3333	struct st_modedef *STm;
3334	struct st_partstat *STps;
3335	char *name = tape_name(STp);
3336	void __user *p = (void __user *)arg;
3337
3338	if (mutex_lock_interruptible(&STp->lock))
3339		return -ERESTARTSYS;
3340
3341        DEB(
3342	if (debugging && !STp->in_use) {
3343		printk(ST_DEB_MSG "%s: Incorrect device.\n", name);
3344		retval = (-EIO);
3345		goto out;
3346	} ) /* end DEB */
3347
3348	STm = &(STp->modes[STp->current_mode]);
3349	STps = &(STp->ps[STp->partition]);
3350
3351	/*
3352	 * If we are in the middle of error recovery, don't let anyone
3353	 * else try and use this device.  Also, if error recovery fails, it
3354	 * may try and take the device offline, in which case all further
3355	 * access to the device is prohibited.
3356	 */
3357	retval = scsi_nonblockable_ioctl(STp->device, cmd_in, p,
3358					file->f_flags & O_NDELAY);
3359	if (!scsi_block_when_processing_errors(STp->device) || retval != -ENODEV)
3360		goto out;
3361	retval = 0;
3362
3363	cmd_type = _IOC_TYPE(cmd_in);
3364	cmd_nr = _IOC_NR(cmd_in);
3365
3366	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3367		struct mtop mtc;
3368
3369		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3370			retval = (-EINVAL);
3371			goto out;
3372		}
3373
3374		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3375		if (i) {
3376			retval = (-EFAULT);
3377			goto out;
3378		}
3379
3380		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3381			printk(KERN_WARNING
3382                               "%s: MTSETDRVBUFFER only allowed for root.\n", name);
3383			retval = (-EPERM);
3384			goto out;
3385		}
3386		if (!STm->defined &&
3387		    (mtc.mt_op != MTSETDRVBUFFER &&
3388		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3389			retval = (-ENXIO);
3390			goto out;
3391		}
3392
3393		if (!STp->pos_unknown) {
3394
3395			if (STps->eof == ST_FM_HIT) {
3396				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3397                                    mtc.mt_op == MTEOM) {
3398					mtc.mt_count -= 1;
3399					if (STps->drv_file >= 0)
3400						STps->drv_file += 1;
3401				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3402					mtc.mt_count += 1;
3403					if (STps->drv_file >= 0)
3404						STps->drv_file += 1;
3405				}
3406			}
3407
3408			if (mtc.mt_op == MTSEEK) {
3409				/* Old position must be restored if partition will be
3410                                   changed */
3411				i = !STp->can_partitions ||
3412				    (STp->new_partition != STp->partition);
3413			} else {
3414				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3415				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3416				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3417				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3418				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3419				    mtc.mt_op == MTCOMPRESSION;
3420			}
3421			i = flush_buffer(STp, i);
3422			if (i < 0) {
3423				retval = i;
3424				goto out;
3425			}
3426			if (STps->rw == ST_WRITING &&
3427			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3428			     mtc.mt_op == MTSEEK ||
3429			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3430				i = st_int_ioctl(STp, MTWEOF, 1);
3431				if (i < 0) {
3432					retval = i;
3433					goto out;
3434				}
3435				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3436					mtc.mt_count++;
3437				STps->rw = ST_IDLE;
3438			     }
3439
3440		} else {
3441			/*
3442			 * If there was a bus reset, block further access
3443			 * to this device.  If the user wants to rewind the tape,
3444			 * then reset the flag and allow access again.
3445			 */
3446			if (mtc.mt_op != MTREW &&
3447			    mtc.mt_op != MTOFFL &&
3448			    mtc.mt_op != MTRETEN &&
3449			    mtc.mt_op != MTERASE &&
3450			    mtc.mt_op != MTSEEK &&
3451			    mtc.mt_op != MTEOM) {
3452				retval = (-EIO);
3453				goto out;
3454			}
3455			reset_state(STp);
3456			/* remove this when the midlevel properly clears was_reset */
3457			STp->device->was_reset = 0;
3458		}
3459
3460		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3461		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3462		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3463			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3464
3465		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3466			do_door_lock(STp, 0);	/* Ignore result! */
3467
3468		if (mtc.mt_op == MTSETDRVBUFFER &&
3469		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3470			retval = st_set_options(STp, mtc.mt_count);
3471			goto out;
3472		}
3473
3474		if (mtc.mt_op == MTSETPART) {
3475			if (!STp->can_partitions ||
3476			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3477				retval = (-EINVAL);
3478				goto out;
3479			}
3480			if (mtc.mt_count >= STp->nbr_partitions &&
3481			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3482				retval = (-EIO);
3483				goto out;
3484			}
3485			if (mtc.mt_count >= STp->nbr_partitions) {
3486				retval = (-EINVAL);
3487				goto out;
3488			}
3489			STp->new_partition = mtc.mt_count;
3490			retval = 0;
3491			goto out;
3492		}
3493
3494		if (mtc.mt_op == MTMKPART) {
3495			if (!STp->can_partitions) {
3496				retval = (-EINVAL);
3497				goto out;
3498			}
3499			if ((i = st_int_ioctl(STp, MTREW, 0)) < 0 ||
3500			    (i = partition_tape(STp, mtc.mt_count)) < 0) {
3501				retval = i;
3502				goto out;
3503			}
3504			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3505				STp->ps[i].rw = ST_IDLE;
3506				STp->ps[i].at_sm = 0;
3507				STp->ps[i].last_block_valid = 0;
3508			}
3509			STp->partition = STp->new_partition = 0;
3510			STp->nbr_partitions = 1;	/* Bad guess ?-) */
3511			STps->drv_block = STps->drv_file = 0;
3512			retval = 0;
3513			goto out;
3514		}
3515
3516		if (mtc.mt_op == MTSEEK) {
3517			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3518			if (!STp->can_partitions)
3519				STp->ps[0].rw = ST_IDLE;
3520			retval = i;
3521			goto out;
3522		}
3523
3524		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3525			retval = do_load_unload(STp, file, 0);
3526			goto out;
3527		}
3528
3529		if (mtc.mt_op == MTLOAD) {
3530			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3531			goto out;
3532		}
3533
3534		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3535			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3536			goto out;
3537		}
3538
3539		if (STp->can_partitions && STp->ready == ST_READY &&
3540		    (i = switch_partition(STp)) < 0) {
3541			retval = i;
3542			goto out;
3543		}
3544
3545		if (mtc.mt_op == MTCOMPRESSION)
3546			retval = st_compression(STp, (mtc.mt_count & 1));
3547		else
3548			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3549		goto out;
3550	}
3551	if (!STm->defined) {
3552		retval = (-ENXIO);
3553		goto out;
3554	}
3555
3556	if ((i = flush_buffer(STp, 0)) < 0) {
3557		retval = i;
3558		goto out;
3559	}
3560	if (STp->can_partitions &&
3561	    (i = switch_partition(STp)) < 0) {
3562		retval = i;
3563		goto out;
3564	}
3565
3566	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3567		struct mtget mt_status;
3568
3569		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3570			 retval = (-EINVAL);
3571			 goto out;
3572		}
3573
3574		mt_status.mt_type = STp->tape_type;
3575		mt_status.mt_dsreg =
3576		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3577		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3578		mt_status.mt_blkno = STps->drv_block;
3579		mt_status.mt_fileno = STps->drv_file;
3580		if (STp->block_size != 0) {
3581			if (STps->rw == ST_WRITING)
3582				mt_status.mt_blkno +=
3583				    (STp->buffer)->buffer_bytes / STp->block_size;
3584			else if (STps->rw == ST_READING)
3585				mt_status.mt_blkno -=
3586                                        ((STp->buffer)->buffer_bytes +
3587                                         STp->block_size - 1) / STp->block_size;
3588		}
3589
3590		mt_status.mt_gstat = 0;
3591		if (STp->drv_write_prot)
3592			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3593		if (mt_status.mt_blkno == 0) {
3594			if (mt_status.mt_fileno == 0)
3595				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3596			else
3597				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3598		}
3599		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3600		mt_status.mt_resid = STp->partition;
3601		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3602			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3603		else if (STps->eof >= ST_EOM_OK)
3604			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3605		if (STp->density == 1)
3606			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3607		else if (STp->density == 2)
3608			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3609		else if (STp->density == 3)
3610			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3611		if (STp->ready == ST_READY)
3612			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3613		if (STp->ready == ST_NO_TAPE)
3614			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3615		if (STps->at_sm)
3616			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3617		if (STm->do_async_writes ||
3618                    (STm->do_buffer_writes && STp->block_size != 0) ||
3619		    STp->drv_buffer != 0)
3620			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3621		if (STp->cleaning_req)
3622			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3623
3624		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3625		if (i) {
3626			retval = (-EFAULT);
3627			goto out;
3628		}
3629
3630		STp->recover_reg = 0;		/* Clear after read */
3631		retval = 0;
3632		goto out;
3633	}			/* End of MTIOCGET */
3634	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3635		struct mtpos mt_pos;
3636		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3637			 retval = (-EINVAL);
3638			 goto out;
3639		}
3640		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3641			retval = i;
3642			goto out;
3643		}
3644		mt_pos.mt_blkno = blk;
3645		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3646		if (i)
3647			retval = (-EFAULT);
3648		goto out;
3649	}
3650	mutex_unlock(&STp->lock);
3651	switch (cmd_in) {
3652		case SCSI_IOCTL_GET_IDLUN:
3653		case SCSI_IOCTL_GET_BUS_NUMBER:
3654			break;
3655		default:
3656			if ((cmd_in == SG_IO ||
3657			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3658			     cmd_in == CDROM_SEND_PACKET) &&
3659			    !capable(CAP_SYS_RAWIO))
3660				i = -EPERM;
3661			else
3662				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3663						   file->f_mode, cmd_in, p);
3664			if (i != -ENOTTY)
3665				return i;
3666			break;
3667	}
3668	retval = scsi_ioctl(STp->device, cmd_in, p);
3669	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
3670		STp->rew_at_close = 0;
3671		STp->ready = ST_NO_TAPE;
3672	}
3673	return retval;
3674
3675 out:
3676	mutex_unlock(&STp->lock);
3677	return retval;
3678}
3679
3680#ifdef CONFIG_COMPAT
3681static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3682{
3683	struct scsi_tape *STp = file->private_data;
3684	struct scsi_device *sdev = STp->device;
3685	int ret = -ENOIOCTLCMD;
3686	if (sdev->host->hostt->compat_ioctl) {
3687
3688		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
3689
3690	}
3691	return ret;
3692}
3693#endif
3694
3695
3696
3697/* Try to allocate a new tape buffer. Calling function must not hold
3698   dev_arr_lock. */
3699static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3700{
3701	struct st_buffer *tb;
3702
3703	tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
3704	if (!tb) {
3705		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3706		return NULL;
3707	}
3708	tb->frp_segs = 0;
3709	tb->use_sg = max_sg;
3710	tb->dma = need_dma;
3711	tb->buffer_size = 0;
3712
3713	tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
3714				     GFP_ATOMIC);
3715	if (!tb->reserved_pages) {
3716		kfree(tb);
3717		return NULL;
3718	}
3719
3720	return tb;
3721}
3722
3723
3724/* Try to allocate enough space in the tape buffer */
3725#define ST_MAX_ORDER 6
3726
3727static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3728{
3729	int segs, nbr, max_segs, b_size, order, got;
3730	gfp_t priority;
3731
3732	if (new_size <= STbuffer->buffer_size)
3733		return 1;
3734
3735	if (STbuffer->buffer_size <= PAGE_SIZE)
3736		normalize_buffer(STbuffer);  /* Avoid extra segment */
3737
3738	max_segs = STbuffer->use_sg;
3739	nbr = max_segs - STbuffer->frp_segs;
3740	if (nbr <= 0)
3741		return 0;
3742
3743	priority = GFP_KERNEL | __GFP_NOWARN;
3744	if (need_dma)
3745		priority |= GFP_DMA;
3746
3747	if (STbuffer->cleared)
3748		priority |= __GFP_ZERO;
3749
3750	if (STbuffer->frp_segs) {
3751		order = STbuffer->reserved_page_order;
3752		b_size = PAGE_SIZE << order;
3753	} else {
3754		for (b_size = PAGE_SIZE, order = 0;
3755		     order < ST_MAX_ORDER &&
3756			     max_segs * (PAGE_SIZE << order) < new_size;
3757		     order++, b_size *= 2)
3758			;  /* empty */
3759		STbuffer->reserved_page_order = order;
3760	}
3761	if (max_segs * (PAGE_SIZE << order) < new_size) {
3762		if (order == ST_MAX_ORDER)
3763			return 0;
3764		normalize_buffer(STbuffer);
3765		return enlarge_buffer(STbuffer, new_size, need_dma);
3766	}
3767
3768	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3769	     segs < max_segs && got < new_size;) {
3770		struct page *page;
3771
3772		page = alloc_pages(priority, order);
3773		if (!page) {
3774			DEB(STbuffer->buffer_size = got);
3775			normalize_buffer(STbuffer);
3776			return 0;
3777		}
3778
3779		STbuffer->frp_segs += 1;
3780		got += b_size;
3781		STbuffer->buffer_size = got;
3782		STbuffer->reserved_pages[segs] = page;
3783		segs++;
3784	}
3785	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3786
3787	return 1;
3788}
3789
3790
3791/* Make sure that no data from previous user is in the internal buffer */
3792static void clear_buffer(struct st_buffer * st_bp)
3793{
3794	int i;
3795
3796	for (i=0; i < st_bp->frp_segs; i++)
3797		memset(page_address(st_bp->reserved_pages[i]), 0,
3798		       PAGE_SIZE << st_bp->reserved_page_order);
3799	st_bp->cleared = 1;
3800}
3801
3802
3803/* Release the extra buffer */
3804static void normalize_buffer(struct st_buffer * STbuffer)
3805{
3806	int i, order = STbuffer->reserved_page_order;
3807
3808	for (i = 0; i < STbuffer->frp_segs; i++) {
3809		__free_pages(STbuffer->reserved_pages[i], order);
3810		STbuffer->buffer_size -= (PAGE_SIZE << order);
3811	}
3812	STbuffer->frp_segs = 0;
3813	STbuffer->sg_segs = 0;
3814	STbuffer->reserved_page_order = 0;
3815	STbuffer->map_data.offset = 0;
3816}
3817
3818
3819/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3820   negative error code. */
3821static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3822{
3823	int i, cnt, res, offset;
3824	int length = PAGE_SIZE << st_bp->reserved_page_order;
3825
3826	for (i = 0, offset = st_bp->buffer_bytes;
3827	     i < st_bp->frp_segs && offset >= length; i++)
3828		offset -= length;
3829	if (i == st_bp->frp_segs) {	/* Should never happen */
3830		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
3831		return (-EIO);
3832	}
3833	for (; i < st_bp->frp_segs && do_count > 0; i++) {
3834		struct page *page = st_bp->reserved_pages[i];
3835		cnt = length - offset < do_count ? length - offset : do_count;
3836		res = copy_from_user(page_address(page) + offset, ubp, cnt);
3837		if (res)
3838			return (-EFAULT);
3839		do_count -= cnt;
3840		st_bp->buffer_bytes += cnt;
3841		ubp += cnt;
3842		offset = 0;
3843	}
3844	if (do_count) /* Should never happen */
3845		return (-EIO);
3846
3847	return 0;
3848}
3849
3850
3851/* Move data from the tape buffer to the user buffer. Returns zero (success) or
3852   negative error code. */
3853static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
3854{
3855	int i, cnt, res, offset;
3856	int length = PAGE_SIZE << st_bp->reserved_page_order;
3857
3858	for (i = 0, offset = st_bp->read_pointer;
3859	     i < st_bp->frp_segs && offset >= length; i++)
3860		offset -= length;
3861	if (i == st_bp->frp_segs) {	/* Should never happen */
3862		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
3863		return (-EIO);
3864	}
3865	for (; i < st_bp->frp_segs && do_count > 0; i++) {
3866		struct page *page = st_bp->reserved_pages[i];
3867		cnt = length - offset < do_count ? length - offset : do_count;
3868		res = copy_to_user(ubp, page_address(page) + offset, cnt);
3869		if (res)
3870			return (-EFAULT);
3871		do_count -= cnt;
3872		st_bp->buffer_bytes -= cnt;
3873		st_bp->read_pointer += cnt;
3874		ubp += cnt;
3875		offset = 0;
3876	}
3877	if (do_count) /* Should never happen */
3878		return (-EIO);
3879
3880	return 0;
3881}
3882
3883
3884/* Move data towards start of buffer */
3885static void move_buffer_data(struct st_buffer * st_bp, int offset)
3886{
3887	int src_seg, dst_seg, src_offset = 0, dst_offset;
3888	int count, total;
3889	int length = PAGE_SIZE << st_bp->reserved_page_order;
3890
3891	if (offset == 0)
3892		return;
3893
3894	total=st_bp->buffer_bytes - offset;
3895	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
3896		src_offset = offset;
3897		if (src_offset < length)
3898			break;
3899		offset -= length;
3900	}
3901
3902	st_bp->buffer_bytes = st_bp->read_pointer = total;
3903	for (dst_seg=dst_offset=0; total > 0; ) {
3904		struct page *dpage = st_bp->reserved_pages[dst_seg];
3905		struct page *spage = st_bp->reserved_pages[src_seg];
3906
3907		count = min(length - dst_offset, length - src_offset);
3908		memmove(page_address(dpage) + dst_offset,
3909			page_address(spage) + src_offset, count);
3910		src_offset += count;
3911		if (src_offset >= length) {
3912			src_seg++;
3913			src_offset = 0;
3914		}
3915		dst_offset += count;
3916		if (dst_offset >= length) {
3917			dst_seg++;
3918			dst_offset = 0;
3919		}
3920		total -= count;
3921	}
3922}
3923
3924/* Validate the options from command line or module parameters */
3925static void validate_options(void)
3926{
3927	if (buffer_kbs > 0)
3928		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
3929	if (max_sg_segs >= ST_FIRST_SG)
3930		st_max_sg_segs = max_sg_segs;
3931}
3932
3933#ifndef MODULE
3934/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
3935 */
3936static int __init st_setup(char *str)
3937{
3938	int i, len, ints[5];
3939	char *stp;
3940
3941	stp = get_options(str, ARRAY_SIZE(ints), ints);
3942
3943	if (ints[0] > 0) {
3944		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
3945			if (parms[i].val)
3946				*parms[i].val = ints[i + 1];
3947	} else {
3948		while (stp != NULL) {
3949			for (i = 0; i < ARRAY_SIZE(parms); i++) {
3950				len = strlen(parms[i].name);
3951				if (!strncmp(stp, parms[i].name, len) &&
3952				    (*(stp + len) == ':' || *(stp + len) == '=')) {
3953					if (parms[i].val)
3954						*parms[i].val =
3955							simple_strtoul(stp + len + 1, NULL, 0);
3956					else
3957						printk(KERN_WARNING "st: Obsolete parameter %s\n",
3958						       parms[i].name);
3959					break;
3960				}
3961			}
3962			if (i >= ARRAY_SIZE(parms))
3963				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
3964					stp);
3965			stp = strchr(stp, ',');
3966			if (stp)
3967				stp++;
3968		}
3969	}
3970
3971	validate_options();
3972
3973	return 1;
3974}
3975
3976__setup("st=", st_setup);
3977
3978#endif
3979
3980static const struct file_operations st_fops =
3981{
3982	.owner =	THIS_MODULE,
3983	.read =		st_read,
3984	.write =	st_write,
3985	.unlocked_ioctl = st_ioctl,
3986#ifdef CONFIG_COMPAT
3987	.compat_ioctl = st_compat_ioctl,
3988#endif
3989	.open =		st_open,
3990	.flush =	st_flush,
3991	.release =	st_release,
3992	.llseek =	noop_llseek,
3993};
3994
3995static int st_probe(struct device *dev)
3996{
3997	struct scsi_device *SDp = to_scsi_device(dev);
3998	struct gendisk *disk = NULL;
3999	struct cdev *cdev = NULL;
4000	struct scsi_tape *tpnt = NULL;
4001	struct st_modedef *STm;
4002	struct st_partstat *STps;
4003	struct st_buffer *buffer;
4004	int i, j, mode, dev_num, error;
4005	char *stp;
4006
4007	if (SDp->type != TYPE_TAPE)
4008		return -ENODEV;
4009	if ((stp = st_incompatible(SDp))) {
4010		sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
4011		printk(KERN_INFO "st: The suggested driver is %s.\n", stp);
4012		return -ENODEV;
4013	}
4014
4015	i = queue_max_segments(SDp->request_queue);
4016	if (st_max_sg_segs < i)
4017		i = st_max_sg_segs;
4018	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4019	if (buffer == NULL) {
4020		printk(KERN_ERR
4021		       "st: Can't allocate new tape buffer. Device not attached.\n");
4022		goto out;
4023	}
4024
4025	disk = alloc_disk(1);
4026	if (!disk) {
4027		printk(KERN_ERR "st: out of memory. Device not attached.\n");
4028		goto out_buffer_free;
4029	}
4030
4031	write_lock(&st_dev_arr_lock);
4032	if (st_nr_dev >= st_dev_max) {
4033		struct scsi_tape **tmp_da;
4034		int tmp_dev_max;
4035
4036		tmp_dev_max = max(st_nr_dev * 2, 8);
4037		if (tmp_dev_max > ST_MAX_TAPES)
4038			tmp_dev_max = ST_MAX_TAPES;
4039		if (tmp_dev_max <= st_nr_dev) {
4040			write_unlock(&st_dev_arr_lock);
4041			printk(KERN_ERR "st: Too many tape devices (max. %d).\n",
4042			       ST_MAX_TAPES);
4043			goto out_put_disk;
4044		}
4045
4046		tmp_da = kzalloc(tmp_dev_max * sizeof(struct scsi_tape *), GFP_ATOMIC);
4047		if (tmp_da == NULL) {
4048			write_unlock(&st_dev_arr_lock);
4049			printk(KERN_ERR "st: Can't extend device array.\n");
4050			goto out_put_disk;
4051		}
4052
4053		if (scsi_tapes != NULL) {
4054			memcpy(tmp_da, scsi_tapes,
4055			       st_dev_max * sizeof(struct scsi_tape *));
4056			kfree(scsi_tapes);
4057		}
4058		scsi_tapes = tmp_da;
4059
4060		st_dev_max = tmp_dev_max;
4061	}
4062
4063	for (i = 0; i < st_dev_max; i++)
4064		if (scsi_tapes[i] == NULL)
4065			break;
4066	if (i >= st_dev_max)
4067		panic("scsi_devices corrupt (st)");
4068
4069	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
4070	if (tpnt == NULL) {
4071		write_unlock(&st_dev_arr_lock);
4072		printk(KERN_ERR "st: Can't allocate device descriptor.\n");
4073		goto out_put_disk;
4074	}
4075	kref_init(&tpnt->kref);
4076	tpnt->disk = disk;
4077	sprintf(disk->disk_name, "st%d", i);
4078	disk->private_data = &tpnt->driver;
4079	disk->queue = SDp->request_queue;
4080	tpnt->driver = &st_template;
4081	scsi_tapes[i] = tpnt;
4082	dev_num = i;
4083
4084	tpnt->device = SDp;
4085	if (SDp->scsi_level <= 2)
4086		tpnt->tape_type = MT_ISSCSI1;
4087	else
4088		tpnt->tape_type = MT_ISSCSI2;
4089
4090	tpnt->buffer = buffer;
4091	tpnt->buffer->last_SRpnt = NULL;
4092
4093	tpnt->inited = 0;
4094	tpnt->dirty = 0;
4095	tpnt->in_use = 0;
4096	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4097	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4098	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4099	tpnt->density = 0;
4100	tpnt->do_auto_lock = ST_AUTO_LOCK;
4101	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4102	tpnt->can_partitions = 0;
4103	tpnt->two_fm = ST_TWO_FM;
4104	tpnt->fast_mteom = ST_FAST_MTEOM;
4105	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4106	tpnt->sili = ST_SILI;
4107	tpnt->immediate = ST_NOWAIT;
4108	tpnt->immediate_filemark = 0;
4109	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4110	tpnt->partition = 0;
4111	tpnt->new_partition = 0;
4112	tpnt->nbr_partitions = 0;
4113	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4114	tpnt->long_timeout = ST_LONG_TIMEOUT;
4115	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4116
4117	for (i = 0; i < ST_NBR_MODES; i++) {
4118		STm = &(tpnt->modes[i]);
4119		STm->defined = 0;
4120		STm->sysv = ST_SYSV;
4121		STm->defaults_for_writes = 0;
4122		STm->do_async_writes = ST_ASYNC_WRITES;
4123		STm->do_buffer_writes = ST_BUFFER_WRITES;
4124		STm->do_read_ahead = ST_READ_AHEAD;
4125		STm->default_compression = ST_DONT_TOUCH;
4126		STm->default_blksize = (-1);	/* No forced size */
4127		STm->default_density = (-1);	/* No forced density */
4128	}
4129
4130	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4131		STps = &(tpnt->ps[i]);
4132		STps->rw = ST_IDLE;
4133		STps->eof = ST_NOEOF;
4134		STps->at_sm = 0;
4135		STps->last_block_valid = 0;
4136		STps->drv_block = (-1);
4137		STps->drv_file = (-1);
4138	}
4139
4140	tpnt->current_mode = 0;
4141	tpnt->modes[0].defined = 1;
4142
4143	tpnt->density_changed = tpnt->compression_changed =
4144	    tpnt->blksize_changed = 0;
4145	mutex_init(&tpnt->lock);
4146
4147	st_nr_dev++;
4148	write_unlock(&st_dev_arr_lock);
4149
4150	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4151		STm = &(tpnt->modes[mode]);
4152		for (j=0; j < 2; j++) {
4153			cdev = cdev_alloc();
4154			if (!cdev) {
4155				printk(KERN_ERR
4156				       "st%d: out of memory. Device not attached.\n",
4157				       dev_num);
4158				goto out_free_tape;
4159			}
4160			cdev->owner = THIS_MODULE;
4161			cdev->ops = &st_fops;
4162
4163			error = cdev_add(cdev,
4164					 MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, j)),
4165					 1);
4166			if (error) {
4167				printk(KERN_ERR "st%d: Can't add %s-rewind mode %d\n",
4168				       dev_num, j ? "non" : "auto", mode);
4169				printk(KERN_ERR "st%d: Device not attached.\n", dev_num);
4170				goto out_free_tape;
4171			}
4172			STm->cdevs[j] = cdev;
4173
4174		}
4175		error = do_create_class_files(tpnt, dev_num, mode);
4176		if (error)
4177			goto out_free_tape;
4178	}
4179	scsi_autopm_put_device(SDp);
4180
4181	sdev_printk(KERN_NOTICE, SDp,
4182		    "Attached scsi tape %s\n", tape_name(tpnt));
4183	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4184		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4185		    queue_dma_alignment(SDp->request_queue) + 1);
4186
4187	return 0;
4188
4189out_free_tape:
4190	for (mode=0; mode < ST_NBR_MODES; mode++) {
4191		STm = &(tpnt->modes[mode]);
4192		sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
4193				  "tape");
4194		for (j=0; j < 2; j++) {
4195			if (STm->cdevs[j]) {
4196				if (cdev == STm->cdevs[j])
4197					cdev = NULL;
4198					device_destroy(st_sysfs_class,
4199						       MKDEV(SCSI_TAPE_MAJOR,
4200							     TAPE_MINOR(i, mode, j)));
4201				cdev_del(STm->cdevs[j]);
4202			}
4203		}
4204	}
4205	if (cdev)
4206		cdev_del(cdev);
4207	write_lock(&st_dev_arr_lock);
4208	scsi_tapes[dev_num] = NULL;
4209	st_nr_dev--;
4210	write_unlock(&st_dev_arr_lock);
4211out_put_disk:
4212	put_disk(disk);
4213	kfree(tpnt);
4214out_buffer_free:
4215	kfree(buffer);
4216out:
4217	return -ENODEV;
4218};
4219
4220
4221static int st_remove(struct device *dev)
4222{
4223	struct scsi_device *SDp = to_scsi_device(dev);
4224	struct scsi_tape *tpnt;
4225	int i, j, mode;
4226
4227	scsi_autopm_get_device(SDp);
4228	write_lock(&st_dev_arr_lock);
4229	for (i = 0; i < st_dev_max; i++) {
4230		tpnt = scsi_tapes[i];
4231		if (tpnt != NULL && tpnt->device == SDp) {
4232			scsi_tapes[i] = NULL;
4233			st_nr_dev--;
4234			write_unlock(&st_dev_arr_lock);
4235			sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
4236					  "tape");
4237			for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4238				for (j=0; j < 2; j++) {
4239					device_destroy(st_sysfs_class,
4240						       MKDEV(SCSI_TAPE_MAJOR,
4241							     TAPE_MINOR(i, mode, j)));
4242					cdev_del(tpnt->modes[mode].cdevs[j]);
4243					tpnt->modes[mode].cdevs[j] = NULL;
4244				}
4245			}
4246
4247			mutex_lock(&st_ref_mutex);
4248			kref_put(&tpnt->kref, scsi_tape_release);
4249			mutex_unlock(&st_ref_mutex);
4250			return 0;
4251		}
4252	}
4253
4254	write_unlock(&st_dev_arr_lock);
4255	return 0;
4256}
4257
4258/**
4259 *      scsi_tape_release - Called to free the Scsi_Tape structure
4260 *      @kref: pointer to embedded kref
4261 *
4262 *      st_ref_mutex must be held entering this routine.  Because it is
4263 *      called on last put, you should always use the scsi_tape_get()
4264 *      scsi_tape_put() helpers which manipulate the semaphore directly
4265 *      and never do a direct kref_put().
4266 **/
4267static void scsi_tape_release(struct kref *kref)
4268{
4269	struct scsi_tape *tpnt = to_scsi_tape(kref);
4270	struct gendisk *disk = tpnt->disk;
4271
4272	tpnt->device = NULL;
4273
4274	if (tpnt->buffer) {
4275		normalize_buffer(tpnt->buffer);
4276		kfree(tpnt->buffer->reserved_pages);
4277		kfree(tpnt->buffer);
4278	}
4279
4280	disk->private_data = NULL;
4281	put_disk(disk);
4282	kfree(tpnt);
4283	return;
4284}
4285
4286static int __init init_st(void)
4287{
4288	int err;
4289
4290	validate_options();
4291
4292	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4293		verstr, st_fixed_buffer_size, st_max_sg_segs);
4294
4295	st_sysfs_class = class_create(THIS_MODULE, "scsi_tape");
4296	if (IS_ERR(st_sysfs_class)) {
4297		printk(KERN_ERR "Unable create sysfs class for SCSI tapes\n");
4298		return PTR_ERR(st_sysfs_class);
4299	}
4300
4301	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4302				     ST_MAX_TAPE_ENTRIES, "st");
4303	if (err) {
4304		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4305		       SCSI_TAPE_MAJOR);
4306		goto err_class;
4307	}
4308
4309	err = scsi_register_driver(&st_template.gendrv);
4310	if (err)
4311		goto err_chrdev;
4312
4313	err = do_create_sysfs_files();
4314	if (err)
4315		goto err_scsidrv;
4316
4317	return 0;
4318
4319err_scsidrv:
4320	scsi_unregister_driver(&st_template.gendrv);
4321err_chrdev:
4322	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4323				 ST_MAX_TAPE_ENTRIES);
4324err_class:
4325	class_destroy(st_sysfs_class);
4326	return err;
4327}
4328
4329static void __exit exit_st(void)
4330{
4331	do_remove_sysfs_files();
4332	scsi_unregister_driver(&st_template.gendrv);
4333	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4334				 ST_MAX_TAPE_ENTRIES);
4335	class_destroy(st_sysfs_class);
4336	kfree(scsi_tapes);
4337	printk(KERN_INFO "st: Unloaded.\n");
4338}
4339
4340module_init(init_st);
4341module_exit(exit_st);
4342
4343
4344/* The sysfs driver interface. Read-only at the moment */
4345static ssize_t st_try_direct_io_show(struct device_driver *ddp, char *buf)
4346{
4347	return snprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4348}
4349static DRIVER_ATTR(try_direct_io, S_IRUGO, st_try_direct_io_show, NULL);
4350
4351static ssize_t st_fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4352{
4353	return snprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4354}
4355static DRIVER_ATTR(fixed_buffer_size, S_IRUGO, st_fixed_buffer_size_show, NULL);
4356
4357static ssize_t st_max_sg_segs_show(struct device_driver *ddp, char *buf)
4358{
4359	return snprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4360}
4361static DRIVER_ATTR(max_sg_segs, S_IRUGO, st_max_sg_segs_show, NULL);
4362
4363static ssize_t st_version_show(struct device_driver *ddd, char *buf)
4364{
4365	return snprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4366}
4367static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL);
4368
4369static int do_create_sysfs_files(void)
4370{
4371	struct device_driver *sysfs = &st_template.gendrv;
4372	int err;
4373
4374	err = driver_create_file(sysfs, &driver_attr_try_direct_io);
4375	if (err)
4376		return err;
4377	err = driver_create_file(sysfs, &driver_attr_fixed_buffer_size);
4378	if (err)
4379		goto err_try_direct_io;
4380	err = driver_create_file(sysfs, &driver_attr_max_sg_segs);
4381	if (err)
4382		goto err_attr_fixed_buf;
4383	err = driver_create_file(sysfs, &driver_attr_version);
4384	if (err)
4385		goto err_attr_max_sg;
4386
4387	return 0;
4388
4389err_attr_max_sg:
4390	driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4391err_attr_fixed_buf:
4392	driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4393err_try_direct_io:
4394	driver_remove_file(sysfs, &driver_attr_try_direct_io);
4395	return err;
4396}
4397
4398static void do_remove_sysfs_files(void)
4399{
4400	struct device_driver *sysfs = &st_template.gendrv;
4401
4402	driver_remove_file(sysfs, &driver_attr_version);
4403	driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4404	driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4405	driver_remove_file(sysfs, &driver_attr_try_direct_io);
4406}
4407
4408
4409/* The sysfs simple class interface */
4410static ssize_t
4411st_defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4412{
4413	struct st_modedef *STm = dev_get_drvdata(dev);
4414	ssize_t l = 0;
4415
4416	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4417	return l;
4418}
4419
4420DEVICE_ATTR(defined, S_IRUGO, st_defined_show, NULL);
4421
4422static ssize_t
4423st_defblk_show(struct device *dev, struct device_attribute *attr, char *buf)
4424{
4425	struct st_modedef *STm = dev_get_drvdata(dev);
4426	ssize_t l = 0;
4427
4428	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4429	return l;
4430}
4431
4432DEVICE_ATTR(default_blksize, S_IRUGO, st_defblk_show, NULL);
4433
4434static ssize_t
4435st_defdensity_show(struct device *dev, struct device_attribute *attr, char *buf)
4436{
4437	struct st_modedef *STm = dev_get_drvdata(dev);
4438	ssize_t l = 0;
4439	char *fmt;
4440
4441	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4442	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4443	return l;
4444}
4445
4446DEVICE_ATTR(default_density, S_IRUGO, st_defdensity_show, NULL);
4447
4448static ssize_t
4449st_defcompression_show(struct device *dev, struct device_attribute *attr,
4450		       char *buf)
4451{
4452	struct st_modedef *STm = dev_get_drvdata(dev);
4453	ssize_t l = 0;
4454
4455	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4456	return l;
4457}
4458
4459DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL);
4460
4461static ssize_t
4462st_options_show(struct device *dev, struct device_attribute *attr, char *buf)
4463{
4464	struct st_modedef *STm = dev_get_drvdata(dev);
4465	struct scsi_tape *STp;
4466	int i, j, options;
4467	ssize_t l = 0;
4468
4469	for (i=0; i < st_dev_max; i++) {
4470		for (j=0; j < ST_NBR_MODES; j++)
4471			if (&scsi_tapes[i]->modes[j] == STm)
4472				break;
4473		if (j < ST_NBR_MODES)
4474			break;
4475	}
4476	if (i == st_dev_max)
4477		return 0;  /* should never happen */
4478
4479	STp = scsi_tapes[i];
4480
4481	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4482	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4483	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4484	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4485	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4486	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4487	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4488	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4489	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4490	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4491	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4492	options |= STm->sysv ? MT_ST_SYSV : 0;
4493	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4494	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4495	options |= STp->sili ? MT_ST_SILI : 0;
4496
4497	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4498	return l;
4499}
4500
4501DEVICE_ATTR(options, S_IRUGO, st_options_show, NULL);
4502
4503static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
4504{
4505	int i, rew, error;
4506	char name[10];
4507	struct device *st_class_member;
4508
4509	for (rew=0; rew < 2; rew++) {
4510		/* Make sure that the minor numbers corresponding to the four
4511		   first modes always get the same names */
4512		i = mode << (4 - ST_NBR_MODE_BITS);
4513		snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4514			 STp->disk->disk_name, st_formats[i]);
4515		st_class_member =
4516			device_create(st_sysfs_class, &STp->device->sdev_gendev,
4517				      MKDEV(SCSI_TAPE_MAJOR,
4518					    TAPE_MINOR(dev_num, mode, rew)),
4519				      &STp->modes[mode], "%s", name);
4520		if (IS_ERR(st_class_member)) {
4521			printk(KERN_WARNING "st%d: device_create failed\n",
4522			       dev_num);
4523			error = PTR_ERR(st_class_member);
4524			goto out;
4525		}
4526
4527		error = device_create_file(st_class_member,
4528					   &dev_attr_defined);
4529		if (error) goto out;
4530		error = device_create_file(st_class_member,
4531					   &dev_attr_default_blksize);
4532		if (error) goto out;
4533		error = device_create_file(st_class_member,
4534					   &dev_attr_default_density);
4535		if (error) goto out;
4536		error = device_create_file(st_class_member,
4537					   &dev_attr_default_compression);
4538		if (error) goto out;
4539		error = device_create_file(st_class_member,
4540					   &dev_attr_options);
4541		if (error) goto out;
4542
4543		if (mode == 0 && rew == 0) {
4544			error = sysfs_create_link(&STp->device->sdev_gendev.kobj,
4545						  &st_class_member->kobj,
4546						  "tape");
4547			if (error) {
4548				printk(KERN_ERR
4549				       "st%d: Can't create sysfs link from SCSI device.\n",
4550				       dev_num);
4551				goto out;
4552			}
4553		}
4554	}
4555
4556	return 0;
4557
4558out:
4559	return error;
4560}
4561
4562/* The following functions may be useful for a larger audience. */
4563static int sgl_map_user_pages(struct st_buffer *STbp,
4564			      const unsigned int max_pages, unsigned long uaddr,
4565			      size_t count, int rw)
4566{
4567	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4568	unsigned long start = uaddr >> PAGE_SHIFT;
4569	const int nr_pages = end - start;
4570	int res, i, j;
4571	struct page **pages;
4572	struct rq_map_data *mdata = &STbp->map_data;
4573
4574	/* User attempted Overflow! */
4575	if ((uaddr + count) < uaddr)
4576		return -EINVAL;
4577
4578	/* Too big */
4579        if (nr_pages > max_pages)
4580		return -ENOMEM;
4581
4582	/* Hmm? */
4583	if (count == 0)
4584		return 0;
4585
4586	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL)
4587		return -ENOMEM;
4588
4589        /* Try to fault in all of the necessary pages */
4590	down_read(&current->mm->mmap_sem);
4591        /* rw==READ means read from drive, write into memory area */
4592	res = get_user_pages(
4593		current,
4594		current->mm,
4595		uaddr,
4596		nr_pages,
4597		rw == READ,
4598		0, /* don't force */
4599		pages,
4600		NULL);
4601	up_read(&current->mm->mmap_sem);
4602
4603	/* Errors and no page mapped should return here */
4604	if (res < nr_pages)
4605		goto out_unmap;
4606
4607        for (i=0; i < nr_pages; i++) {
4608                /* FIXME: flush superflous for rw==READ,
4609                 * probably wrong function for rw==WRITE
4610                 */
4611		flush_dcache_page(pages[i]);
4612        }
4613
4614	mdata->offset = uaddr & ~PAGE_MASK;
4615	STbp->mapped_pages = pages;
4616
4617	return nr_pages;
4618 out_unmap:
4619	if (res > 0) {
4620		for (j=0; j < res; j++)
4621			page_cache_release(pages[j]);
4622		res = 0;
4623	}
4624	kfree(pages);
4625	return res;
4626}
4627
4628
4629/* And unmap them... */
4630static int sgl_unmap_user_pages(struct st_buffer *STbp,
4631				const unsigned int nr_pages, int dirtied)
4632{
4633	int i;
4634
4635	for (i=0; i < nr_pages; i++) {
4636		struct page *page = STbp->mapped_pages[i];
4637
4638		if (dirtied)
4639			SetPageDirty(page);
4640		/* FIXME: cache flush missing for rw==READ
4641		 * FIXME: call the correct reference counting function
4642		 */
4643		page_cache_release(page);
4644	}
4645	kfree(STbp->mapped_pages);
4646	STbp->mapped_pages = NULL;
4647
4648	return 0;
4649}
4650