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Diffstat (limited to 'drivers/s390/char/tape_block.c')
-rw-r--r--drivers/s390/char/tape_block.c444
1 files changed, 0 insertions, 444 deletions
diff --git a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c
deleted file mode 100644
index 1b3924c2fff..00000000000
--- a/drivers/s390/char/tape_block.c
+++ /dev/null
@@ -1,444 +0,0 @@
1/*
2 * drivers/s390/char/tape_block.c
3 * block device frontend for tape device driver
4 *
5 * S390 and zSeries version
6 * Copyright (C) 2001,2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
7 * Author(s): Carsten Otte <cotte@de.ibm.com>
8 * Tuan Ngo-Anh <ngoanh@de.ibm.com>
9 * Martin Schwidefsky <schwidefsky@de.ibm.com>
10 * Stefan Bader <shbader@de.ibm.com>
11 */
12
13#define KMSG_COMPONENT "tape"
14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16#include <linux/fs.h>
17#include <linux/module.h>
18#include <linux/blkdev.h>
19#include <linux/mutex.h>
20#include <linux/interrupt.h>
21#include <linux/buffer_head.h>
22#include <linux/kernel.h>
23
24#include <asm/debug.h>
25
26#define TAPE_DBF_AREA tape_core_dbf
27
28#include "tape.h"
29
30#define TAPEBLOCK_MAX_SEC 100
31#define TAPEBLOCK_MIN_REQUEUE 3
32
33/*
34 * 2003/11/25 Stefan Bader <shbader@de.ibm.com>
35 *
36 * In 2.5/2.6 the block device request function is very likely to be called
37 * with disabled interrupts (e.g. generic_unplug_device). So the driver can't
38 * just call any function that tries to allocate CCW requests from that con-
39 * text since it might sleep. There are two choices to work around this:
40 * a) do not allocate with kmalloc but use its own memory pool
41 * b) take requests from the queue outside that context, knowing that
42 * allocation might sleep
43 */
44
45/*
46 * file operation structure for tape block frontend
47 */
48static DEFINE_MUTEX(tape_block_mutex);
49static int tapeblock_open(struct block_device *, fmode_t);
50static int tapeblock_release(struct gendisk *, fmode_t);
51static unsigned int tapeblock_check_events(struct gendisk *, unsigned int);
52static int tapeblock_revalidate_disk(struct gendisk *);
53
54static const struct block_device_operations tapeblock_fops = {
55 .owner = THIS_MODULE,
56 .open = tapeblock_open,
57 .release = tapeblock_release,
58 .check_events = tapeblock_check_events,
59 .revalidate_disk = tapeblock_revalidate_disk,
60};
61
62static int tapeblock_major = 0;
63
64static void
65tapeblock_trigger_requeue(struct tape_device *device)
66{
67 /* Protect against rescheduling. */
68 if (atomic_cmpxchg(&device->blk_data.requeue_scheduled, 0, 1) != 0)
69 return;
70 schedule_work(&device->blk_data.requeue_task);
71}
72
73/*
74 * Post finished request.
75 */
76static void
77__tapeblock_end_request(struct tape_request *ccw_req, void *data)
78{
79 struct tape_device *device;
80 struct request *req;
81
82 DBF_LH(6, "__tapeblock_end_request()\n");
83
84 device = ccw_req->device;
85 req = (struct request *) data;
86 blk_end_request_all(req, (ccw_req->rc == 0) ? 0 : -EIO);
87 if (ccw_req->rc == 0)
88 /* Update position. */
89 device->blk_data.block_position =
90 (blk_rq_pos(req) + blk_rq_sectors(req)) >> TAPEBLOCK_HSEC_S2B;
91 else
92 /* We lost the position information due to an error. */
93 device->blk_data.block_position = -1;
94 device->discipline->free_bread(ccw_req);
95 if (!list_empty(&device->req_queue) ||
96 blk_peek_request(device->blk_data.request_queue))
97 tapeblock_trigger_requeue(device);
98}
99
100/*
101 * Feed the tape device CCW queue with requests supplied in a list.
102 */
103static int
104tapeblock_start_request(struct tape_device *device, struct request *req)
105{
106 struct tape_request * ccw_req;
107 int rc;
108
109 DBF_LH(6, "tapeblock_start_request(%p, %p)\n", device, req);
110
111 ccw_req = device->discipline->bread(device, req);
112 if (IS_ERR(ccw_req)) {
113 DBF_EVENT(1, "TBLOCK: bread failed\n");
114 blk_end_request_all(req, -EIO);
115 return PTR_ERR(ccw_req);
116 }
117 ccw_req->callback = __tapeblock_end_request;
118 ccw_req->callback_data = (void *) req;
119 ccw_req->retries = TAPEBLOCK_RETRIES;
120
121 rc = tape_do_io_async(device, ccw_req);
122 if (rc) {
123 /*
124 * Start/enqueueing failed. No retries in
125 * this case.
126 */
127 blk_end_request_all(req, -EIO);
128 device->discipline->free_bread(ccw_req);
129 }
130
131 return rc;
132}
133
134/*
135 * Move requests from the block device request queue to the tape device ccw
136 * queue.
137 */
138static void
139tapeblock_requeue(struct work_struct *work) {
140 struct tape_blk_data * blkdat;
141 struct tape_device * device;
142 struct request_queue * queue;
143 int nr_queued;
144 struct request * req;
145 struct list_head * l;
146 int rc;
147
148 blkdat = container_of(work, struct tape_blk_data, requeue_task);
149 device = blkdat->device;
150 if (!device)
151 return;
152
153 spin_lock_irq(get_ccwdev_lock(device->cdev));
154 queue = device->blk_data.request_queue;
155
156 /* Count number of requests on ccw queue. */
157 nr_queued = 0;
158 list_for_each(l, &device->req_queue)
159 nr_queued++;
160 spin_unlock(get_ccwdev_lock(device->cdev));
161
162 spin_lock_irq(&device->blk_data.request_queue_lock);
163 while (
164 blk_peek_request(queue) &&
165 nr_queued < TAPEBLOCK_MIN_REQUEUE
166 ) {
167 req = blk_fetch_request(queue);
168 if (rq_data_dir(req) == WRITE) {
169 DBF_EVENT(1, "TBLOCK: Rejecting write request\n");
170 spin_unlock_irq(&device->blk_data.request_queue_lock);
171 blk_end_request_all(req, -EIO);
172 spin_lock_irq(&device->blk_data.request_queue_lock);
173 continue;
174 }
175 nr_queued++;
176 spin_unlock_irq(&device->blk_data.request_queue_lock);
177 rc = tapeblock_start_request(device, req);
178 spin_lock_irq(&device->blk_data.request_queue_lock);
179 }
180 spin_unlock_irq(&device->blk_data.request_queue_lock);
181 atomic_set(&device->blk_data.requeue_scheduled, 0);
182}
183
184/*
185 * Tape request queue function. Called from ll_rw_blk.c
186 */
187static void
188tapeblock_request_fn(struct request_queue *queue)
189{
190 struct tape_device *device;
191
192 device = (struct tape_device *) queue->queuedata;
193 DBF_LH(6, "tapeblock_request_fn(device=%p)\n", device);
194 BUG_ON(device == NULL);
195 tapeblock_trigger_requeue(device);
196}
197
198/*
199 * This function is called for every new tapedevice
200 */
201int
202tapeblock_setup_device(struct tape_device * device)
203{
204 struct tape_blk_data * blkdat;
205 struct gendisk * disk;
206 int rc;
207
208 blkdat = &device->blk_data;
209 blkdat->device = device;
210 spin_lock_init(&blkdat->request_queue_lock);
211 atomic_set(&blkdat->requeue_scheduled, 0);
212
213 blkdat->request_queue = blk_init_queue(
214 tapeblock_request_fn,
215 &blkdat->request_queue_lock
216 );
217 if (!blkdat->request_queue)
218 return -ENOMEM;
219
220 rc = elevator_change(blkdat->request_queue, "noop");
221 if (rc)
222 goto cleanup_queue;
223
224 blk_queue_logical_block_size(blkdat->request_queue, TAPEBLOCK_HSEC_SIZE);
225 blk_queue_max_hw_sectors(blkdat->request_queue, TAPEBLOCK_MAX_SEC);
226 blk_queue_max_segments(blkdat->request_queue, -1L);
227 blk_queue_max_segment_size(blkdat->request_queue, -1L);
228 blk_queue_segment_boundary(blkdat->request_queue, -1L);
229
230 disk = alloc_disk(1);
231 if (!disk) {
232 rc = -ENOMEM;
233 goto cleanup_queue;
234 }
235
236 disk->major = tapeblock_major;
237 disk->first_minor = device->first_minor;
238 disk->fops = &tapeblock_fops;
239 disk->private_data = tape_get_device(device);
240 disk->queue = blkdat->request_queue;
241 set_capacity(disk, 0);
242 sprintf(disk->disk_name, "btibm%d",
243 device->first_minor / TAPE_MINORS_PER_DEV);
244
245 blkdat->disk = disk;
246 blkdat->medium_changed = 1;
247 blkdat->request_queue->queuedata = tape_get_device(device);
248
249 add_disk(disk);
250
251 tape_get_device(device);
252 INIT_WORK(&blkdat->requeue_task, tapeblock_requeue);
253
254 return 0;
255
256cleanup_queue:
257 blk_cleanup_queue(blkdat->request_queue);
258 blkdat->request_queue = NULL;
259
260 return rc;
261}
262
263void
264tapeblock_cleanup_device(struct tape_device *device)
265{
266 flush_work_sync(&device->blk_data.requeue_task);
267 tape_put_device(device);
268
269 if (!device->blk_data.disk) {
270 goto cleanup_queue;
271 }
272
273 del_gendisk(device->blk_data.disk);
274 device->blk_data.disk->private_data = NULL;
275 tape_put_device(device);
276 put_disk(device->blk_data.disk);
277
278 device->blk_data.disk = NULL;
279cleanup_queue:
280 device->blk_data.request_queue->queuedata = NULL;
281 tape_put_device(device);
282
283 blk_cleanup_queue(device->blk_data.request_queue);
284 device->blk_data.request_queue = NULL;
285}
286
287/*
288 * Detect number of blocks of the tape.
289 * FIXME: can we extent this to detect the blocks size as well ?
290 */
291static int
292tapeblock_revalidate_disk(struct gendisk *disk)
293{
294 struct tape_device * device;
295 unsigned int nr_of_blks;
296 int rc;
297
298 device = (struct tape_device *) disk->private_data;
299 BUG_ON(!device);
300
301 if (!device->blk_data.medium_changed)
302 return 0;
303
304 rc = tape_mtop(device, MTFSFM, 1);
305 if (rc)
306 return rc;
307
308 rc = tape_mtop(device, MTTELL, 1);
309 if (rc < 0)
310 return rc;
311
312 pr_info("%s: Determining the size of the recorded area...\n",
313 dev_name(&device->cdev->dev));
314 DBF_LH(3, "Image file ends at %d\n", rc);
315 nr_of_blks = rc;
316
317 /* This will fail for the first file. Catch the error by checking the
318 * position. */
319 tape_mtop(device, MTBSF, 1);
320
321 rc = tape_mtop(device, MTTELL, 1);
322 if (rc < 0)
323 return rc;
324
325 if (rc > nr_of_blks)
326 return -EINVAL;
327
328 DBF_LH(3, "Image file starts at %d\n", rc);
329 device->bof = rc;
330 nr_of_blks -= rc;
331
332 pr_info("%s: The size of the recorded area is %i blocks\n",
333 dev_name(&device->cdev->dev), nr_of_blks);
334 set_capacity(device->blk_data.disk,
335 nr_of_blks*(TAPEBLOCK_HSEC_SIZE/512));
336
337 device->blk_data.block_position = 0;
338 device->blk_data.medium_changed = 0;
339 return 0;
340}
341
342static unsigned int
343tapeblock_check_events(struct gendisk *disk, unsigned int clearing)
344{
345 struct tape_device *device;
346
347 device = (struct tape_device *) disk->private_data;
348 DBF_LH(6, "tapeblock_medium_changed(%p) = %d\n",
349 device, device->blk_data.medium_changed);
350
351 return device->blk_data.medium_changed ? DISK_EVENT_MEDIA_CHANGE : 0;
352}
353
354/*
355 * Block frontend tape device open function.
356 */
357static int
358tapeblock_open(struct block_device *bdev, fmode_t mode)
359{
360 struct gendisk * disk = bdev->bd_disk;
361 struct tape_device * device;
362 int rc;
363
364 mutex_lock(&tape_block_mutex);
365 device = tape_get_device(disk->private_data);
366
367 if (device->required_tapemarks) {
368 DBF_EVENT(2, "TBLOCK: missing tapemarks\n");
369 pr_warning("%s: Opening the tape failed because of missing "
370 "end-of-file marks\n", dev_name(&device->cdev->dev));
371 rc = -EPERM;
372 goto put_device;
373 }
374
375 rc = tape_open(device);
376 if (rc)
377 goto put_device;
378
379 rc = tapeblock_revalidate_disk(disk);
380 if (rc)
381 goto release;
382
383 /*
384 * Note: The reference to <device> is hold until the release function
385 * is called.
386 */
387 tape_state_set(device, TS_BLKUSE);
388 mutex_unlock(&tape_block_mutex);
389 return 0;
390
391release:
392 tape_release(device);
393 put_device:
394 tape_put_device(device);
395 mutex_unlock(&tape_block_mutex);
396 return rc;
397}
398
399/*
400 * Block frontend tape device release function.
401 *
402 * Note: One reference to the tape device was made by the open function. So
403 * we just get the pointer here and release the reference.
404 */
405static int
406tapeblock_release(struct gendisk *disk, fmode_t mode)
407{
408 struct tape_device *device = disk->private_data;
409
410 mutex_lock(&tape_block_mutex);
411 tape_state_set(device, TS_IN_USE);
412 tape_release(device);
413 tape_put_device(device);
414 mutex_unlock(&tape_block_mutex);
415
416 return 0;
417}
418
419/*
420 * Initialize block device frontend.
421 */
422int
423tapeblock_init(void)
424{
425 int rc;
426
427 /* Register the tape major number to the kernel */
428 rc = register_blkdev(tapeblock_major, "tBLK");
429 if (rc < 0)
430 return rc;
431
432 if (tapeblock_major == 0)
433 tapeblock_major = rc;
434 return 0;
435}
436
437/*
438 * Deregister major for block device frontend
439 */
440void
441tapeblock_exit(void)
442{
443 unregister_blkdev(tapeblock_major, "tBLK");
444}
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