drivers/block/pktcdvd.c

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   4  *
   5  * May be copied or modified under the terms of the GNU General Public
   6  * License.  See linux/COPYING for more information.
   7  *
   8  * Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
   9  * DVD-RAM devices.
  10  *
  11  * Theory of operation:
  12  *
  13  * At the lowest level, there is the standard driver for the CD/DVD device,
  14  * typically ide-cd.c or sr.c. This driver can handle read and write requests,
  15  * but it doesn't know anything about the special restrictions that apply to
  16  * packet writing. One restriction is that write requests must be aligned to
  17  * packet boundaries on the physical media, and the size of a write request
  18  * must be equal to the packet size. Another restriction is that a
  19  * GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
  20  * command, if the previous command was a write.
  21  *
  22  * The purpose of the packet writing driver is to hide these restrictions from
  23  * higher layers, such as file systems, and present a block device that can be
  24  * randomly read and written using 2kB-sized blocks.
  25  *
  26  * The lowest layer in the packet writing driver is the packet I/O scheduler.
  27  * Its data is defined by the struct packet_iosched and includes two bio
  28  * queues with pending read and write requests. These queues are processed
  29  * by the pkt_iosched_process_queue() function. The write requests in this
  30  * queue are already properly aligned and sized. This layer is responsible for
  31  * issuing the flush cache commands and scheduling the I/O in a good order.
  32  *
  33  * The next layer transforms unaligned write requests to aligned writes. This
  34  * transformation requires reading missing pieces of data from the underlying
  35  * block device, assembling the pieces to full packets and queuing them to the
  36  * packet I/O scheduler.
  37  *
  38  * At the top layer there is a custom make_request_fn function that forwards
  39  * read requests directly to the iosched queue and puts write requests in the
  40  * unaligned write queue. A kernel thread performs the necessary read
  41  * gathering to convert the unaligned writes to aligned writes and then feeds
  42  * them to the packet I/O scheduler.
  43  *
  44  *************************************************************************/
  45
  46 #define VERSION_CODE    "v0.2.0a 2004-07-14 Jens Axboe (axboe@suse.de) and petero2@telia.com"
  47
  48 #include <linux/pktcdvd.h>
  49 #include <linux/config.h>
  50 #include <linux/module.h>
  51 #include <linux/types.h>
  52 #include <linux/kernel.h>
  53 #include <linux/kthread.h>
  54 #include <linux/errno.h>
  55 #include <linux/spinlock.h>
  56 #include <linux/file.h>
  57 #include <linux/proc_fs.h>
  58 #include <linux/seq_file.h>
  59 #include <linux/miscdevice.h>
  60 #include <linux/suspend.h>
  61 #include <scsi/scsi_cmnd.h>
  62 #include <scsi/scsi_ioctl.h>
  63
  64 #include <asm/uaccess.h>
  65
  66 #if PACKET_DEBUG
  67 #define DPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
  68 #else
  69 #define DPRINTK(fmt, args...)
  70 #endif
  71
  72 #if PACKET_DEBUG > 1
  73 #define VPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
  74 #else
  75 #define VPRINTK(fmt, args...)
  76 #endif
  77
  78 #define MAX_SPEED 0xffff
  79
  80 #define ZONE(sector, pd) (((sector) + (pd)->offset) & ~((pd)->settings.size - 1))
  81
  82 static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
  83 static struct proc_dir_entry *pkt_proc;
  84 static int pkt_major;
  85 static struct semaphore ctl_mutex;      /* Serialize open/close/setup/teardown */
  86 static mempool_t *psd_pool;
  87
  88
  89 static void pkt_bio_finished(struct pktcdvd_device *pd)
  90 {
  91         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
  92         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
  93                 VPRINTK("pktcdvd: queue empty\n");
  94                 atomic_set(&pd->iosched.attention, 1);
  95                 wake_up(&pd->wqueue);
  96         }
  97 }
  98
  99 static void pkt_bio_destructor(struct bio *bio)
 100 {
 101         kfree(bio->bi_io_vec);
 102         kfree(bio);
 103 }
 104
 105 static struct bio *pkt_bio_alloc(int nr_iovecs)
 106 {
 107         struct bio_vec *bvl = NULL;
 108         struct bio *bio;
 109
 110         bio = kmalloc(sizeof(struct bio), GFP_KERNEL);
 111         if (!bio)
 112                 goto no_bio;
 113         bio_init(bio);
 114
 115         bvl = kcalloc(nr_iovecs, sizeof(struct bio_vec), GFP_KERNEL);
 116         if (!bvl)
 117                 goto no_bvl;
 118
 119         bio->bi_max_vecs = nr_iovecs;
 120         bio->bi_io_vec = bvl;
 121         bio->bi_destructor = pkt_bio_destructor;
 122
 123         return bio;
 124
 125  no_bvl:
 126         kfree(bio);
 127  no_bio:
 128         return NULL;
 129 }
 130
 131 /*
 132  * Allocate a packet_data struct
 133  */
 134 static struct packet_data *pkt_alloc_packet_data(void)
 135 {
 136         int i;
 137         struct packet_data *pkt;
 138
 139         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 140         if (!pkt)
 141                 goto no_pkt;
 142
 143         pkt->w_bio = pkt_bio_alloc(PACKET_MAX_SIZE);
 144         if (!pkt->w_bio)
 145                 goto no_bio;
 146
 147         for (i = 0; i < PAGES_PER_PACKET; i++) {
 148                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 149                 if (!pkt->pages[i])
 150                         goto no_page;
 151         }
 152
 153         spin_lock_init(&pkt->lock);
 154
 155         for (i = 0; i < PACKET_MAX_SIZE; i++) {
 156                 struct bio *bio = pkt_bio_alloc(1);
 157                 if (!bio)
 158                         goto no_rd_bio;
 159                 pkt->r_bios[i] = bio;
 160         }
 161
 162         return pkt;
 163
 164 no_rd_bio:
 165         for (i = 0; i < PACKET_MAX_SIZE; i++) {
 166                 struct bio *bio = pkt->r_bios[i];
 167                 if (bio)
 168                         bio_put(bio);
 169         }
 170
 171 no_page:
 172         for (i = 0; i < PAGES_PER_PACKET; i++)
 173                 if (pkt->pages[i])
 174                         __free_page(pkt->pages[i]);
 175         bio_put(pkt->w_bio);
 176 no_bio:
 177         kfree(pkt);
 178 no_pkt:
 179         return NULL;
 180 }
 181
 182 /*
 183  * Free a packet_data struct
 184  */
 185 static void pkt_free_packet_data(struct packet_data *pkt)
 186 {
 187         int i;
 188
 189         for (i = 0; i < PACKET_MAX_SIZE; i++) {
 190                 struct bio *bio = pkt->r_bios[i];
 191                 if (bio)
 192                         bio_put(bio);
 193         }
 194         for (i = 0; i < PAGES_PER_PACKET; i++)
 195                 __free_page(pkt->pages[i]);
 196         bio_put(pkt->w_bio);
 197         kfree(pkt);
 198 }
 199
 200 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 201 {
 202         struct packet_data *pkt, *next;
 203
 204         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 205
 206         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 207                 pkt_free_packet_data(pkt);
 208         }
 209 }
 210
 211 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 212 {
 213         struct packet_data *pkt;
 214
 215         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 216         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
 217         spin_lock_init(&pd->cdrw.active_list_lock);
 218         while (nr_packets > 0) {
 219                 pkt = pkt_alloc_packet_data();
 220                 if (!pkt) {
 221                         pkt_shrink_pktlist(pd);
 222                         return 0;
 223                 }
 224                 pkt->id = nr_packets;
 225                 pkt->pd = pd;
 226                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 227                 nr_packets--;
 228         }
 229         return 1;
 230 }
 231
 232 static void *pkt_rb_alloc(unsigned int __nocast gfp_mask, void *data)
 233 {
 234         return kmalloc(sizeof(struct pkt_rb_node), gfp_mask);
 235 }
 236
 237 static void pkt_rb_free(void *ptr, void *data)
 238 {
 239         kfree(ptr);
 240 }
 241
 242 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 243 {
 244         struct rb_node *n = rb_next(&node->rb_node);
 245         if (!n)
 246                 return NULL;
 247         return rb_entry(n, struct pkt_rb_node, rb_node);
 248 }
 249
 250 static inline void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 251 {
 252         rb_erase(&node->rb_node, &pd->bio_queue);
 253         mempool_free(node, pd->rb_pool);
 254         pd->bio_queue_size--;
 255         BUG_ON(pd->bio_queue_size < 0);
 256 }
 257
 258 /*
 259  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 260  */
 261 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 262 {
 263         struct rb_node *n = pd->bio_queue.rb_node;
 264         struct rb_node *next;
 265         struct pkt_rb_node *tmp;
 266
 267         if (!n) {
 268                 BUG_ON(pd->bio_queue_size > 0);
 269                 return NULL;
 270         }
 271
 272         for (;;) {
 273                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 274                 if (s <= tmp->bio->bi_sector)
 275                         next = n->rb_left;
 276                 else
 277                         next = n->rb_right;
 278                 if (!next)
 279                         break;
 280                 n = next;
 281         }
 282
 283         if (s > tmp->bio->bi_sector) {
 284                 tmp = pkt_rbtree_next(tmp);
 285                 if (!tmp)
 286                         return NULL;
 287         }
 288         BUG_ON(s > tmp->bio->bi_sector);
 289         return tmp;
 290 }
 291
 292 /*
 293  * Insert a node into the pd->bio_queue rb tree.
 294  */
 295 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 296 {
 297         struct rb_node **p = &pd->bio_queue.rb_node;
 298         struct rb_node *parent = NULL;
 299         sector_t s = node->bio->bi_sector;
 300         struct pkt_rb_node *tmp;
 301
 302         while (*p) {
 303                 parent = *p;
 304                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 305                 if (s < tmp->bio->bi_sector)
 306                         p = &(*p)->rb_left;
 307                 else
 308                         p = &(*p)->rb_right;
 309         }
 310         rb_link_node(&node->rb_node, parent, p);
 311         rb_insert_color(&node->rb_node, &pd->bio_queue);
 312         pd->bio_queue_size++;
 313 }
 314
 315 /*
 316  * Add a bio to a single linked list defined by its head and tail pointers.
 317  */
 318 static inline void pkt_add_list_last(struct bio *bio, struct bio **list_head, struct bio **list_tail)
 319 {
 320         bio->bi_next = NULL;
 321         if (*list_tail) {
 322                 BUG_ON((*list_head) == NULL);
 323                 (*list_tail)->bi_next = bio;
 324                 (*list_tail) = bio;
 325         } else {
 326                 BUG_ON((*list_head) != NULL);
 327                 (*list_head) = bio;
 328                 (*list_tail) = bio;
 329         }
 330 }
 331
 332 /*
 333  * Remove and return the first bio from a single linked list defined by its
 334  * head and tail pointers.
 335  */
 336 static inline struct bio *pkt_get_list_first(struct bio **list_head, struct bio **list_tail)
 337 {
 338         struct bio *bio;
 339
 340         if (*list_head == NULL)
 341                 return NULL;
 342
 343         bio = *list_head;
 344         *list_head = bio->bi_next;
 345         if (*list_head == NULL)
 346                 *list_tail = NULL;
 347
 348         bio->bi_next = NULL;
 349         return bio;
 350 }
 351
 352 /*
 353  * Send a packet_command to the underlying block device and
 354  * wait for completion.
 355  */
 356 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 357 {
 358         char sense[SCSI_SENSE_BUFFERSIZE];
 359         request_queue_t *q;
 360         struct request *rq;
 361         DECLARE_COMPLETION(wait);
 362         int err = 0;
 363
 364         q = bdev_get_queue(pd->bdev);
 365
 366         rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ? WRITE : READ,
 367                              __GFP_WAIT);
 368         rq->errors = 0;
 369         rq->rq_disk = pd->bdev->bd_disk;
 370         rq->bio = NULL;
 371         rq->buffer = NULL;
 372         rq->timeout = 60*HZ;
 373         rq->data = cgc->buffer;
 374         rq->data_len = cgc->buflen;
 375         rq->sense = sense;
 376         memset(sense, 0, sizeof(sense));
 377         rq->sense_len = 0;
 378         rq->flags |= REQ_BLOCK_PC | REQ_HARDBARRIER;
 379         if (cgc->quiet)
 380                 rq->flags |= REQ_QUIET;
 381         memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 382         if (sizeof(rq->cmd) > CDROM_PACKET_SIZE)
 383                 memset(rq->cmd + CDROM_PACKET_SIZE, 0, sizeof(rq->cmd) - CDROM_PACKET_SIZE);
 384
 385         rq->ref_count++;
 386         rq->flags |= REQ_NOMERGE;
 387         rq->waiting = &wait;
 388         rq->end_io = blk_end_sync_rq;
 389         elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 1);
 390         generic_unplug_device(q);
 391         wait_for_completion(&wait);
 392
 393         if (rq->errors)
 394                 err = -EIO;
 395
 396         blk_put_request(rq);
 397         return err;
 398 }
 399
 400 /*
 401  * A generic sense dump / resolve mechanism should be implemented across
 402  * all ATAPI + SCSI devices.
 403  */
 404 static void pkt_dump_sense(struct packet_command *cgc)
 405 {
 406         static char *info[9] = { "No sense", "Recovered error", "Not ready",
 407                                  "Medium error", "Hardware error", "Illegal request",
 408                                  "Unit attention", "Data protect", "Blank check" };
 409         int i;
 410         struct request_sense *sense = cgc->sense;
 411
 412         printk("pktcdvd:");
 413         for (i = 0; i < CDROM_PACKET_SIZE; i++)
 414                 printk(" %02x", cgc->cmd[i]);
 415         printk(" - ");
 416
 417         if (sense == NULL) {
 418                 printk("no sense\n");
 419                 return;
 420         }
 421
 422         printk("sense %02x.%02x.%02x", sense->sense_key, sense->asc, sense->ascq);
 423
 424         if (sense->sense_key > 8) {
 425                 printk(" (INVALID)\n");
 426                 return;
 427         }
 428
 429         printk(" (%s)\n", info[sense->sense_key]);
 430 }
 431
 432 /*
 433  * flush the drive cache to media
 434  */
 435 static int pkt_flush_cache(struct pktcdvd_device *pd)
 436 {
 437         struct packet_command cgc;
 438
 439         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 440         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 441         cgc.quiet = 1;
 442
 443         /*
 444          * the IMMED bit -- we default to not setting it, although that
 445          * would allow a much faster close, this is safer
 446          */
 447 #if 0
 448         cgc.cmd[1] = 1 << 1;
 449 #endif
 450         return pkt_generic_packet(pd, &cgc);
 451 }
 452
 453 /*
 454  * speed is given as the normal factor, e.g. 4 for 4x
 455  */
 456 static int pkt_set_speed(struct pktcdvd_device *pd, unsigned write_speed, unsigned read_speed)
 457 {
 458         struct packet_command cgc;
 459         struct request_sense sense;
 460         int ret;
 461
 462         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 463         cgc.sense = &sense;
 464         cgc.cmd[0] = GPCMD_SET_SPEED;
 465         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 466         cgc.cmd[3] = read_speed & 0xff;
 467         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 468         cgc.cmd[5] = write_speed & 0xff;
 469
 470         if ((ret = pkt_generic_packet(pd, &cgc)))
 471                 pkt_dump_sense(&cgc);
 472
 473         return ret;
 474 }
 475
 476 /*
 477  * Queue a bio for processing by the low-level CD device. Must be called
 478  * from process context.
 479  */
 480 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 481 {
 482         spin_lock(&pd->iosched.lock);
 483         if (bio_data_dir(bio) == READ) {
 484                 pkt_add_list_last(bio, &pd->iosched.read_queue,
 485                                   &pd->iosched.read_queue_tail);
 486         } else {
 487                 pkt_add_list_last(bio, &pd->iosched.write_queue,
 488                                   &pd->iosched.write_queue_tail);
 489         }
 490         spin_unlock(&pd->iosched.lock);
 491
 492         atomic_set(&pd->iosched.attention, 1);
 493         wake_up(&pd->wqueue);
 494 }
 495
 496 /*
 497  * Process the queued read/write requests. This function handles special
 498  * requirements for CDRW drives:
 499  * - A cache flush command must be inserted before a read request if the
 500  *   previous request was a write.
 501  * - Switching between reading and writing is slow, so don't do it more often
 502  *   than necessary.
 503  * - Optimize for throughput at the expense of latency. This means that streaming
 504  *   writes will never be interrupted by a read, but if the drive has to seek
 505  *   before the next write, switch to reading instead if there are any pending
 506  *   read requests.
 507  * - Set the read speed according to current usage pattern. When only reading
 508  *   from the device, it's best to use the highest possible read speed, but
 509  *   when switching often between reading and writing, it's better to have the
 510  *   same read and write speeds.
 511  */
 512 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 513 {
 514         request_queue_t *q;
 515
 516         if (atomic_read(&pd->iosched.attention) == 0)
 517                 return;
 518         atomic_set(&pd->iosched.attention, 0);
 519
 520         q = bdev_get_queue(pd->bdev);
 521
 522         for (;;) {
 523                 struct bio *bio;
 524                 int reads_queued, writes_queued;
 525
 526                 spin_lock(&pd->iosched.lock);
 527                 reads_queued = (pd->iosched.read_queue != NULL);
 528                 writes_queued = (pd->iosched.write_queue != NULL);
 529                 spin_unlock(&pd->iosched.lock);
 530
 531                 if (!reads_queued && !writes_queued)
 532                         break;
 533
 534                 if (pd->iosched.writing) {
 535                         int need_write_seek = 1;
 536                         spin_lock(&pd->iosched.lock);
 537                         bio = pd->iosched.write_queue;
 538                         spin_unlock(&pd->iosched.lock);
 539                         if (bio && (bio->bi_sector == pd->iosched.last_write))
 540                                 need_write_seek = 0;
 541                         if (need_write_seek && reads_queued) {
 542                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 543                                         VPRINTK("pktcdvd: write, waiting\n");
 544                                         break;
 545                                 }
 546                                 pkt_flush_cache(pd);
 547                                 pd->iosched.writing = 0;
 548                         }
 549                 } else {
 550                         if (!reads_queued && writes_queued) {
 551                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 552                                         VPRINTK("pktcdvd: read, waiting\n");
 553                                         break;
 554                                 }
 555                                 pd->iosched.writing = 1;
 556                         }
 557                 }
 558
 559                 spin_lock(&pd->iosched.lock);
 560                 if (pd->iosched.writing) {
 561                         bio = pkt_get_list_first(&pd->iosched.write_queue,
 562                                                  &pd->iosched.write_queue_tail);
 563                 } else {
 564                         bio = pkt_get_list_first(&pd->iosched.read_queue,
 565                                                  &pd->iosched.read_queue_tail);
 566                 }
 567                 spin_unlock(&pd->iosched.lock);
 568
 569                 if (!bio)
 570                         continue;
 571
 572                 if (bio_data_dir(bio) == READ)
 573                         pd->iosched.successive_reads += bio->bi_size >> 10;
 574                 else {
 575                         pd->iosched.successive_reads = 0;
 576                         pd->iosched.last_write = bio->bi_sector + bio_sectors(bio);
 577                 }
 578                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 579                         if (pd->read_speed == pd->write_speed) {
 580                                 pd->read_speed = MAX_SPEED;
 581                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 582                         }
 583                 } else {
 584                         if (pd->read_speed != pd->write_speed) {
 585                                 pd->read_speed = pd->write_speed;
 586                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 587                         }
 588                 }
 589
 590                 atomic_inc(&pd->cdrw.pending_bios);
 591                 generic_make_request(bio);
 592         }
 593 }
 594
 595 /*
 596  * Special care is needed if the underlying block device has a small
 597  * max_phys_segments value.
 598  */
 599 static int pkt_set_segment_merging(struct pktcdvd_device *pd, request_queue_t *q)
 600 {
 601         if ((pd->settings.size << 9) / CD_FRAMESIZE <= q->max_phys_segments) {
 602                 /*
 603                  * The cdrom device can handle one segment/frame
 604                  */
 605                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 606                 return 0;
 607         } else if ((pd->settings.size << 9) / PAGE_SIZE <= q->max_phys_segments) {
 608                 /*
 609                  * We can handle this case at the expense of some extra memory
 610                  * copies during write operations
 611                  */
 612                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 613                 return 0;
 614         } else {
 615                 printk("pktcdvd: cdrom max_phys_segments too small\n");
 616                 return -EIO;
 617         }
 618 }
 619
 620 /*
 621  * Copy CD_FRAMESIZE bytes from src_bio into a destination page
 622  */
 623 static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
 624 {
 625         unsigned int copy_size = CD_FRAMESIZE;
 626
 627         while (copy_size > 0) {
 628                 struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
 629                 void *vfrom = kmap_atomic(src_bvl->bv_page, KM_USER0) +
 630                         src_bvl->bv_offset + offs;
 631                 void *vto = page_address(dst_page) + dst_offs;
 632                 int len = min_t(int, copy_size, src_bvl->bv_len - offs);
 633
 634                 BUG_ON(len < 0);
 635                 memcpy(vto, vfrom, len);
 636                 kunmap_atomic(vfrom, KM_USER0);
 637
 638                 seg++;
 639                 offs = 0;
 640                 dst_offs += len;
 641                 copy_size -= len;
 642         }
 643 }
 644
 645 /*
 646  * Copy all data for this packet to pkt->pages[], so that
 647  * a) The number of required segments for the write bio is minimized, which
 648  *    is necessary for some scsi controllers.
 649  * b) The data can be used as cache to avoid read requests if we receive a
 650  *    new write request for the same zone.
 651  */
 652 static void pkt_make_local_copy(struct packet_data *pkt, struct page **pages, int *offsets)
 653 {
 654         int f, p, offs;
 655
 656         /* Copy all data to pkt->pages[] */
 657         p = 0;
 658         offs = 0;
 659         for (f = 0; f < pkt->frames; f++) {
 660                 if (pages[f] != pkt->pages[p]) {
 661                         void *vfrom = kmap_atomic(pages[f], KM_USER0) + offsets[f];
 662                         void *vto = page_address(pkt->pages[p]) + offs;
 663                         memcpy(vto, vfrom, CD_FRAMESIZE);
 664                         kunmap_atomic(vfrom, KM_USER0);
 665                         pages[f] = pkt->pages[p];
 666                         offsets[f] = offs;
 667                 } else {
 668                         BUG_ON(offsets[f] != offs);
 669                 }
 670                 offs += CD_FRAMESIZE;
 671                 if (offs >= PAGE_SIZE) {
 672                         BUG_ON(offs > PAGE_SIZE);
 673                         offs = 0;
 674                         p++;
 675                 }
 676         }
 677 }
 678
 679 static int pkt_end_io_read(struct bio *bio, unsigned int bytes_done, int err)
 680 {
 681         struct packet_data *pkt = bio->bi_private;
 682         struct pktcdvd_device *pd = pkt->pd;
 683         BUG_ON(!pd);
 684
 685         if (bio->bi_size)
 686                 return 1;
 687
 688         VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
 689                 (unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
 690
 691         if (err)
 692                 atomic_inc(&pkt->io_errors);
 693         if (atomic_dec_and_test(&pkt->io_wait)) {
 694                 atomic_inc(&pkt->run_sm);
 695                 wake_up(&pd->wqueue);
 696         }
 697         pkt_bio_finished(pd);
 698
 699         return 0;
 700 }
 701
 702 static int pkt_end_io_packet_write(struct bio *bio, unsigned int bytes_done, int err)
 703 {
 704         struct packet_data *pkt = bio->bi_private;
 705         struct pktcdvd_device *pd = pkt->pd;
 706         BUG_ON(!pd);
 707
 708         if (bio->bi_size)
 709                 return 1;
 710
 711         VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
 712
 713         pd->stats.pkt_ended++;
 714
 715         pkt_bio_finished(pd);
 716         atomic_dec(&pkt->io_wait);
 717         atomic_inc(&pkt->run_sm);
 718         wake_up(&pd->wqueue);
 719         return 0;
 720 }
 721
 722 /*
 723  * Schedule reads for the holes in a packet
 724  */
 725 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
 726 {
 727         int frames_read = 0;
 728         struct bio *bio;
 729         int f;
 730         char written[PACKET_MAX_SIZE];
 731
 732         BUG_ON(!pkt->orig_bios);
 733
 734         atomic_set(&pkt->io_wait, 0);
 735         atomic_set(&pkt->io_errors, 0);
 736
 737         /*
 738          * Figure out which frames we need to read before we can write.
 739          */
 740         memset(written, 0, sizeof(written));
 741         spin_lock(&pkt->lock);
 742         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
 743                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
 744                 int num_frames = bio->bi_size / CD_FRAMESIZE;
 745                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
 746                 BUG_ON(first_frame < 0);
 747                 BUG_ON(first_frame + num_frames > pkt->frames);
 748                 for (f = first_frame; f < first_frame + num_frames; f++)
 749                         written[f] = 1;
 750         }
 751         spin_unlock(&pkt->lock);
 752
 753         if (pkt->cache_valid) {
 754                 VPRINTK("pkt_gather_data: zone %llx cached\n",
 755                         (unsigned long long)pkt->sector);
 756                 goto out_account;
 757         }
 758
 759         /*
 760          * Schedule reads for missing parts of the packet.
 761          */
 762         for (f = 0; f < pkt->frames; f++) {
 763                 int p, offset;
 764                 if (written[f])
 765                         continue;
 766                 bio = pkt->r_bios[f];
 767                 bio_init(bio);
 768                 bio->bi_max_vecs = 1;
 769                 bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
 770                 bio->bi_bdev = pd->bdev;
 771                 bio->bi_end_io = pkt_end_io_read;
 772                 bio->bi_private = pkt;
 773
 774                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
 775                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
 776                 VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
 777                         f, pkt->pages[p], offset);
 778                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
 779                         BUG();
 780
 781                 atomic_inc(&pkt->io_wait);
 782                 bio->bi_rw = READ;
 783                 pkt_queue_bio(pd, bio);
 784                 frames_read++;
 785         }
 786
 787 out_account:
 788         VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
 789                 frames_read, (unsigned long long)pkt->sector);
 790         pd->stats.pkt_started++;
 791         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
 792 }
 793
 794 /*
 795  * Find a packet matching zone, or the least recently used packet if
 796  * there is no match.
 797  */
 798 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
 799 {
 800         struct packet_data *pkt;
 801
 802         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
 803                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
 804                         list_del_init(&pkt->list);
 805                         if (pkt->sector != zone)
 806                                 pkt->cache_valid = 0;
 807                         break;
 808                 }
 809         }
 810         return pkt;
 811 }
 812
 813 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
 814 {
 815         if (pkt->cache_valid) {
 816                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 817         } else {
 818                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
 819         }
 820 }
 821
 822 /*
 823  * recover a failed write, query for relocation if possible
 824  *
 825  * returns 1 if recovery is possible, or 0 if not
 826  *
 827  */
 828 static int pkt_start_recovery(struct packet_data *pkt)
 829 {
 830         /*
 831          * FIXME. We need help from the file system to implement
 832          * recovery handling.
 833          */
 834         return 0;
 835 #if 0
 836         struct request *rq = pkt->rq;
 837         struct pktcdvd_device *pd = rq->rq_disk->private_data;
 838         struct block_device *pkt_bdev;
 839         struct super_block *sb = NULL;
 840         unsigned long old_block, new_block;
 841         sector_t new_sector;
 842
 843         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
 844         if (pkt_bdev) {
 845                 sb = get_super(pkt_bdev);
 846                 bdput(pkt_bdev);
 847         }
 848
 849         if (!sb)
 850                 return 0;
 851
 852         if (!sb->s_op || !sb->s_op->relocate_blocks)
 853                 goto out;
 854
 855         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
 856         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
 857                 goto out;
 858
 859         new_sector = new_block * (CD_FRAMESIZE >> 9);
 860         pkt->sector = new_sector;
 861
 862         pkt->bio->bi_sector = new_sector;
 863         pkt->bio->bi_next = NULL;
 864         pkt->bio->bi_flags = 1 << BIO_UPTODATE;
 865         pkt->bio->bi_idx = 0;
 866
 867         BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
 868         BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
 869         BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
 870         BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
 871         BUG_ON(pkt->bio->bi_private != pkt);
 872
 873         drop_super(sb);
 874         return 1;
 875
 876 out:
 877         drop_super(sb);
 878         return 0;
 879 #endif
 880 }
 881
 882 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
 883 {
 884 #if PACKET_DEBUG > 1
 885         static const char *state_name[] = {
 886                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
 887         };
 888         enum packet_data_state old_state = pkt->state;
 889         VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
 890                 state_name[old_state], state_name[state]);
 891 #endif
 892         pkt->state = state;
 893 }
 894
 895 /*
 896  * Scan the work queue to see if we can start a new packet.
 897  * returns non-zero if any work was done.
 898  */
 899 static int pkt_handle_queue(struct pktcdvd_device *pd)
 900 {
 901         struct packet_data *pkt, *p;
 902         struct bio *bio = NULL;
 903         sector_t zone = 0; /* Suppress gcc warning */
 904         struct pkt_rb_node *node, *first_node;
 905         struct rb_node *n;
 906
 907         VPRINTK("handle_queue\n");
 908
 909         atomic_set(&pd->scan_queue, 0);
 910
 911         if (list_empty(&pd->cdrw.pkt_free_list)) {
 912                 VPRINTK("handle_queue: no pkt\n");
 913                 return 0;
 914         }
 915
 916         /*
 917          * Try to find a zone we are not already working on.
 918          */
 919         spin_lock(&pd->lock);
 920         first_node = pkt_rbtree_find(pd, pd->current_sector);
 921         if (!first_node) {
 922                 n = rb_first(&pd->bio_queue);
 923                 if (n)
 924                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
 925         }
 926         node = first_node;
 927         while (node) {
 928                 bio = node->bio;
 929                 zone = ZONE(bio->bi_sector, pd);
 930                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
 931                         if (p->sector == zone) {
 932                                 bio = NULL;
 933                                 goto try_next_bio;
 934                         }
 935                 }
 936                 break;
 937 try_next_bio:
 938                 node = pkt_rbtree_next(node);
 939                 if (!node) {
 940                         n = rb_first(&pd->bio_queue);
 941                         if (n)
 942                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
 943                 }
 944                 if (node == first_node)
 945                         node = NULL;
 946         }
 947         spin_unlock(&pd->lock);
 948         if (!bio) {
 949                 VPRINTK("handle_queue: no bio\n");
 950                 return 0;
 951         }
 952
 953         pkt = pkt_get_packet_data(pd, zone);
 954         BUG_ON(!pkt);
 955
 956         pd->current_sector = zone + pd->settings.size;
 957         pkt->sector = zone;
 958         pkt->frames = pd->settings.size >> 2;
 959         pkt->write_size = 0;
 960
 961         /*
 962          * Scan work queue for bios in the same zone and link them
 963          * to this packet.
 964          */
 965         spin_lock(&pd->lock);
 966         VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
 967         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
 968                 bio = node->bio;
 969                 VPRINTK("pkt_handle_queue: found zone=%llx\n",
 970                         (unsigned long long)ZONE(bio->bi_sector, pd));
 971                 if (ZONE(bio->bi_sector, pd) != zone)
 972                         break;
 973                 pkt_rbtree_erase(pd, node);
 974                 spin_lock(&pkt->lock);
 975                 pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
 976                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
 977                 spin_unlock(&pkt->lock);
 978         }
 979         spin_unlock(&pd->lock);
 980
 981         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
 982         pkt_set_state(pkt, PACKET_WAITING_STATE);
 983         atomic_set(&pkt->run_sm, 1);
 984
 985         spin_lock(&pd->cdrw.active_list_lock);
 986         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
 987         spin_unlock(&pd->cdrw.active_list_lock);
 988
 989         return 1;
 990 }
 991
 992 /*
 993  * Assemble a bio to write one packet and queue the bio for processing
 994  * by the underlying block device.
 995  */
 996 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
 997 {
 998         struct bio *bio;
 999         struct page *pages[PACKET_MAX_SIZE];
1000         int offsets[PACKET_MAX_SIZE];
1001         int f;
1002         int frames_write;
1003
1004         for (f = 0; f < pkt->frames; f++) {
1005                 pages[f] = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1006                 offsets[f] = (f * CD_FRAMESIZE) % PAGE_SIZE;
1007         }
1008
1009         /*
1010          * Fill-in pages[] and offsets[] with data from orig_bios.
1011          */
1012         frames_write = 0;
1013         spin_lock(&pkt->lock);
1014         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1015                 int segment = bio->bi_idx;
1016                 int src_offs = 0;
1017                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1018                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1019                 BUG_ON(first_frame < 0);
1020                 BUG_ON(first_frame + num_frames > pkt->frames);
1021                 for (f = first_frame; f < first_frame + num_frames; f++) {
1022                         struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
1023
1024                         while (src_offs >= src_bvl->bv_len) {
1025                                 src_offs -= src_bvl->bv_len;
1026                                 segment++;
1027                                 BUG_ON(segment >= bio->bi_vcnt);
1028                                 src_bvl = bio_iovec_idx(bio, segment);
1029                         }
1030
1031                         if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
1032                                 pages[f] = src_bvl->bv_page;
1033                                 offsets[f] = src_bvl->bv_offset + src_offs;
1034                         } else {
1035                                 pkt_copy_bio_data(bio, segment, src_offs,
1036                                                   pages[f], offsets[f]);
1037                         }
1038                         src_offs += CD_FRAMESIZE;
1039                         frames_write++;
1040                 }
1041         }
1042         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1043         spin_unlock(&pkt->lock);
1044
1045         VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
1046                 frames_write, (unsigned long long)pkt->sector);
1047         BUG_ON(frames_write != pkt->write_size);
1048
1049         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1050                 pkt_make_local_copy(pkt, pages, offsets);
1051                 pkt->cache_valid = 1;
1052         } else {
1053                 pkt->cache_valid = 0;
1054         }
1055
1056         /* Start the write request */
1057         bio_init(pkt->w_bio);
1058         pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
1059         pkt->w_bio->bi_sector = pkt->sector;
1060         pkt->w_bio->bi_bdev = pd->bdev;
1061         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1062         pkt->w_bio->bi_private = pkt;
1063         for (f = 0; f < pkt->frames; f++) {
1064                 if ((f + 1 < pkt->frames) && (pages[f + 1] == pages[f]) &&
1065                     (offsets[f + 1] = offsets[f] + CD_FRAMESIZE)) {
1066                         if (!bio_add_page(pkt->w_bio, pages[f], CD_FRAMESIZE * 2, offsets[f]))
1067                                 BUG();
1068                         f++;
1069                 } else {
1070                         if (!bio_add_page(pkt->w_bio, pages[f], CD_FRAMESIZE, offsets[f]))
1071                                 BUG();
1072                 }
1073         }
1074         VPRINTK("pktcdvd: vcnt=%d\n", pkt->w_bio->bi_vcnt);
1075
1076         atomic_set(&pkt->io_wait, 1);
1077         pkt->w_bio->bi_rw = WRITE;
1078         pkt_queue_bio(pd, pkt->w_bio);
1079 }
1080
1081 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1082 {
1083         struct bio *bio, *next;
1084
1085         if (!uptodate)
1086                 pkt->cache_valid = 0;
1087
1088         /* Finish all bios corresponding to this packet */
1089         bio = pkt->orig_bios;
1090         while (bio) {
1091                 next = bio->bi_next;
1092                 bio->bi_next = NULL;
1093                 bio_endio(bio, bio->bi_size, uptodate ? 0 : -EIO);
1094                 bio = next;
1095         }
1096         pkt->orig_bios = pkt->orig_bios_tail = NULL;
1097 }
1098
1099 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1100 {
1101         int uptodate;
1102
1103         VPRINTK("run_state_machine: pkt %d\n", pkt->id);
1104
1105         for (;;) {
1106                 switch (pkt->state) {
1107                 case PACKET_WAITING_STATE:
1108                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1109                                 return;
1110
1111                         pkt->sleep_time = 0;
1112                         pkt_gather_data(pd, pkt);
1113                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1114                         break;
1115
1116                 case PACKET_READ_WAIT_STATE:
1117                         if (atomic_read(&pkt->io_wait) > 0)
1118                                 return;
1119
1120                         if (atomic_read(&pkt->io_errors) > 0) {
1121                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1122                         } else {
1123                                 pkt_start_write(pd, pkt);
1124                         }
1125                         break;
1126
1127                 case PACKET_WRITE_WAIT_STATE:
1128                         if (atomic_read(&pkt->io_wait) > 0)
1129                                 return;
1130
1131                         if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1132                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1133                         } else {
1134                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1135                         }
1136                         break;
1137
1138                 case PACKET_RECOVERY_STATE:
1139                         if (pkt_start_recovery(pkt)) {
1140                                 pkt_start_write(pd, pkt);
1141                         } else {
1142                                 VPRINTK("No recovery possible\n");
1143                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1144                         }
1145                         break;
1146
1147                 case PACKET_FINISHED_STATE:
1148                         uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1149                         pkt_finish_packet(pkt, uptodate);
1150                         return;
1151
1152                 default:
1153                         BUG();
1154                         break;
1155                 }
1156         }
1157 }
1158
1159 static void pkt_handle_packets(struct pktcdvd_device *pd)
1160 {
1161         struct packet_data *pkt, *next;
1162
1163         VPRINTK("pkt_handle_packets\n");
1164
1165         /*
1166          * Run state machine for active packets
1167          */
1168         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1169                 if (atomic_read(&pkt->run_sm) > 0) {
1170                         atomic_set(&pkt->run_sm, 0);
1171                         pkt_run_state_machine(pd, pkt);
1172                 }
1173         }
1174
1175         /*
1176          * Move no longer active packets to the free list
1177          */
1178         spin_lock(&pd->cdrw.active_list_lock);
1179         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1180                 if (pkt->state == PACKET_FINISHED_STATE) {
1181                         list_del(&pkt->list);
1182                         pkt_put_packet_data(pd, pkt);
1183                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1184                         atomic_set(&pd->scan_queue, 1);
1185                 }
1186         }
1187         spin_unlock(&pd->cdrw.active_list_lock);
1188 }
1189
1190 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1191 {
1192         struct packet_data *pkt;
1193         int i;
1194
1195         for (i = 0; i <= PACKET_NUM_STATES; i++)
1196                 states[i] = 0;
1197
1198         spin_lock(&pd->cdrw.active_list_lock);
1199         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1200                 states[pkt->state]++;
1201         }
1202         spin_unlock(&pd->cdrw.active_list_lock);
1203 }
1204
1205 /*
1206  * kcdrwd is woken up when writes have been queued for one of our
1207  * registered devices
1208  */
1209 static int kcdrwd(void *foobar)
1210 {
1211         struct pktcdvd_device *pd = foobar;
1212         struct packet_data *pkt;
1213         long min_sleep_time, residue;
1214
1215         set_user_nice(current, -20);
1216
1217         for (;;) {
1218                 DECLARE_WAITQUEUE(wait, current);
1219
1220                 /*
1221                  * Wait until there is something to do
1222                  */
1223                 add_wait_queue(&pd->wqueue, &wait);
1224                 for (;;) {
1225                         set_current_state(TASK_INTERRUPTIBLE);
1226
1227                         /* Check if we need to run pkt_handle_queue */
1228                         if (atomic_read(&pd->scan_queue) > 0)
1229                                 goto work_to_do;
1230
1231                         /* Check if we need to run the state machine for some packet */
1232                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1233                                 if (atomic_read(&pkt->run_sm) > 0)
1234                                         goto work_to_do;
1235                         }
1236
1237                         /* Check if we need to process the iosched queues */
1238                         if (atomic_read(&pd->iosched.attention) != 0)
1239                                 goto work_to_do;
1240
1241                         /* Otherwise, go to sleep */
1242                         if (PACKET_DEBUG > 1) {
1243                                 int states[PACKET_NUM_STATES];
1244                                 pkt_count_states(pd, states);
1245                                 VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1246                                         states[0], states[1], states[2], states[3],
1247                                         states[4], states[5]);
1248                         }
1249
1250                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1251                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1252                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1253                                         min_sleep_time = pkt->sleep_time;
1254                         }
1255
1256                         generic_unplug_device(bdev_get_queue(pd->bdev));
1257
1258                         VPRINTK("kcdrwd: sleeping\n");
1259                         residue = schedule_timeout(min_sleep_time);
1260                         VPRINTK("kcdrwd: wake up\n");
1261
1262                         /* make swsusp happy with our thread */
1263                         try_to_freeze();
1264
1265                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1266                                 if (!pkt->sleep_time)
1267                                         continue;
1268                                 pkt->sleep_time -= min_sleep_time - residue;
1269                                 if (pkt->sleep_time <= 0) {
1270                                         pkt->sleep_time = 0;
1271                                         atomic_inc(&pkt->run_sm);
1272                                 }
1273                         }
1274
1275                         if (signal_pending(current)) {
1276                                 flush_signals(current);
1277                         }
1278                         if (kthread_should_stop())
1279                                 break;
1280                 }
1281 work_to_do:
1282                 set_current_state(TASK_RUNNING);
1283                 remove_wait_queue(&pd->wqueue, &wait);
1284
1285                 if (kthread_should_stop())
1286                         break;
1287
1288                 /*
1289                  * if pkt_handle_queue returns true, we can queue
1290                  * another request.
1291                  */
1292                 while (pkt_handle_queue(pd))
1293                         ;
1294
1295                 /*
1296                  * Handle packet state machine
1297                  */
1298                 pkt_handle_packets(pd);
1299
1300                 /*
1301                  * Handle iosched queues
1302                  */
1303                 pkt_iosched_process_queue(pd);
1304         }
1305
1306         return 0;
1307 }
1308
1309 static void pkt_print_settings(struct pktcdvd_device *pd)
1310 {
1311         printk("pktcdvd: %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
1312         printk("%u blocks, ", pd->settings.size >> 2);
1313         printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
1314 }
1315
1316 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1317 {
1318         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1319
1320         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1321         cgc->cmd[2] = page_code | (page_control << 6);
1322         cgc->cmd[7] = cgc->buflen >> 8;
1323         cgc->cmd[8] = cgc->buflen & 0xff;
1324         cgc->data_direction = CGC_DATA_READ;
1325         return pkt_generic_packet(pd, cgc);
1326 }
1327
1328 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1329 {
1330         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1331         memset(cgc->buffer, 0, 2);
1332         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1333         cgc->cmd[1] = 0x10;             /* PF */
1334         cgc->cmd[7] = cgc->buflen >> 8;
1335         cgc->cmd[8] = cgc->buflen & 0xff;
1336         cgc->data_direction = CGC_DATA_WRITE;
1337         return pkt_generic_packet(pd, cgc);
1338 }
1339
1340 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1341 {
1342         struct packet_command cgc;
1343         int ret;
1344
1345         /* set up command and get the disc info */
1346         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1347         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1348         cgc.cmd[8] = cgc.buflen = 2;
1349         cgc.quiet = 1;
1350
1351         if ((ret = pkt_generic_packet(pd, &cgc)))
1352                 return ret;
1353
1354         /* not all drives have the same disc_info length, so requeue
1355          * packet with the length the drive tells us it can supply
1356          */
1357         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1358                      sizeof(di->disc_information_length);
1359
1360         if (cgc.buflen > sizeof(disc_information))
1361                 cgc.buflen = sizeof(disc_information);
1362
1363         cgc.cmd[8] = cgc.buflen;
1364         return pkt_generic_packet(pd, &cgc);
1365 }
1366
1367 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1368 {
1369         struct packet_command cgc;
1370         int ret;
1371
1372         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1373         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1374         cgc.cmd[1] = type & 3;
1375         cgc.cmd[4] = (track & 0xff00) >> 8;
1376         cgc.cmd[5] = track & 0xff;
1377         cgc.cmd[8] = 8;
1378         cgc.quiet = 1;
1379
1380         if ((ret = pkt_generic_packet(pd, &cgc)))
1381                 return ret;
1382
1383         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1384                      sizeof(ti->track_information_length);
1385
1386         if (cgc.buflen > sizeof(track_information))
1387                 cgc.buflen = sizeof(track_information);
1388
1389         cgc.cmd[8] = cgc.buflen;
1390         return pkt_generic_packet(pd, &cgc);
1391 }
1392
1393 static int pkt_get_last_written(struct pktcdvd_device *pd, long *last_written)
1394 {
1395         disc_information di;
1396         track_information ti;
1397         __u32 last_track;
1398         int ret = -1;
1399
1400         if ((ret = pkt_get_disc_info(pd, &di)))
1401                 return ret;
1402
1403         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1404         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1405                 return ret;
1406
1407         /* if this track is blank, try the previous. */
1408         if (ti.blank) {
1409                 last_track--;
1410                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1411                         return ret;
1412         }
1413
1414         /* if last recorded field is valid, return it. */
1415         if (ti.lra_v) {
1416                 *last_written = be32_to_cpu(ti.last_rec_address);
1417         } else {
1418                 /* make it up instead */
1419                 *last_written = be32_to_cpu(ti.track_start) +
1420                                 be32_to_cpu(ti.track_size);
1421                 if (ti.free_blocks)
1422                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1423         }
1424         return 0;
1425 }
1426
1427 /*
1428  * write mode select package based on pd->settings
1429  */
1430 static int pkt_set_write_settings(struct pktcdvd_device *pd)
1431 {
1432         struct packet_command cgc;
1433         struct request_sense sense;
1434         write_param_page *wp;
1435         char buffer[128];
1436         int ret, size;
1437
1438         /* doesn't apply to DVD+RW or DVD-RAM */
1439         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1440                 return 0;
1441
1442         memset(buffer, 0, sizeof(buffer));
1443         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1444         cgc.sense = &sense;
1445         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1446                 pkt_dump_sense(&cgc);
1447                 return ret;
1448         }
1449
1450         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1451         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1452         if (size > sizeof(buffer))
1453                 size = sizeof(buffer);
1454
1455         /*
1456          * now get it all
1457          */
1458         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1459         cgc.sense = &sense;
1460         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1461                 pkt_dump_sense(&cgc);
1462                 return ret;
1463         }
1464
1465         /*
1466          * write page is offset header + block descriptor length
1467          */
1468         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1469
1470         wp->fp = pd->settings.fp;
1471         wp->track_mode = pd->settings.track_mode;
1472         wp->write_type = pd->settings.write_type;
1473         wp->data_block_type = pd->settings.block_mode;
1474
1475         wp->multi_session = 0;
1476
1477 #ifdef PACKET_USE_LS
1478         wp->link_size = 7;
1479         wp->ls_v = 1;
1480 #endif
1481
1482         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1483                 wp->session_format = 0;
1484                 wp->subhdr2 = 0x20;
1485         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1486                 wp->session_format = 0x20;
1487                 wp->subhdr2 = 8;
1488 #if 0
1489                 wp->mcn[0] = 0x80;
1490                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1491 #endif
1492         } else {
1493                 /*
1494                  * paranoia
1495                  */
1496                 printk("pktcdvd: write mode wrong %d\n", wp->data_block_type);
1497                 return 1;
1498         }
1499         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1500
1501         cgc.buflen = cgc.cmd[8] = size;
1502         if ((ret = pkt_mode_select(pd, &cgc))) {
1503                 pkt_dump_sense(&cgc);
1504                 return ret;
1505         }
1506
1507         pkt_print_settings(pd);
1508         return 0;
1509 }
1510
1511 /*
1512  * 0 -- we can write to this track, 1 -- we can't
1513  */
1514 static int pkt_good_track(track_information *ti)
1515 {
1516         /*
1517          * only good for CD-RW at the moment, not DVD-RW
1518          */
1519
1520         /*
1521          * FIXME: only for FP
1522          */
1523         if (ti->fp == 0)
1524                 return 0;
1525
1526         /*
1527          * "good" settings as per Mt Fuji.
1528          */
1529         if (ti->rt == 0 && ti->blank == 0 && ti->packet == 1)
1530                 return 0;
1531
1532         if (ti->rt == 0 && ti->blank == 1 && ti->packet == 1)
1533                 return 0;
1534
1535         if (ti->rt == 1 && ti->blank == 0 && ti->packet == 1)
1536                 return 0;
1537
1538         printk("pktcdvd: bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1539         return 1;
1540 }
1541
1542 /*
1543  * 0 -- we can write to this disc, 1 -- we can't
1544  */
1545 static int pkt_good_disc(struct pktcdvd_device *pd, disc_information *di)
1546 {
1547         switch (pd->mmc3_profile) {
1548                 case 0x0a: /* CD-RW */
1549                 case 0xffff: /* MMC3 not supported */
1550                         break;
1551                 case 0x1a: /* DVD+RW */
1552                 case 0x13: /* DVD-RW */
1553                 case 0x12: /* DVD-RAM */
1554                         return 0;
1555                 default:
1556                         printk("pktcdvd: Wrong disc profile (%x)\n", pd->mmc3_profile);
1557                         return 1;
1558         }
1559
1560         /*
1561          * for disc type 0xff we should probably reserve a new track.
1562          * but i'm not sure, should we leave this to user apps? probably.
1563          */
1564         if (di->disc_type == 0xff) {
1565                 printk("pktcdvd: Unknown disc. No track?\n");
1566                 return 1;
1567         }
1568
1569         if (di->disc_type != 0x20 && di->disc_type != 0) {
1570                 printk("pktcdvd: Wrong disc type (%x)\n", di->disc_type);
1571                 return 1;
1572         }
1573
1574         if (di->erasable == 0) {
1575                 printk("pktcdvd: Disc not erasable\n");
1576                 return 1;
1577         }
1578
1579         if (di->border_status == PACKET_SESSION_RESERVED) {
1580                 printk("pktcdvd: Can't write to last track (reserved)\n");
1581                 return 1;
1582         }
1583
1584         return 0;
1585 }
1586
1587 static int pkt_probe_settings(struct pktcdvd_device *pd)
1588 {
1589         struct packet_command cgc;
1590         unsigned char buf[12];
1591         disc_information di;
1592         track_information ti;
1593         int ret, track;
1594
1595         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1596         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1597         cgc.cmd[8] = 8;
1598         ret = pkt_generic_packet(pd, &cgc);
1599         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1600
1601         memset(&di, 0, sizeof(disc_information));
1602         memset(&ti, 0, sizeof(track_information));
1603
1604         if ((ret = pkt_get_disc_info(pd, &di))) {
1605                 printk("failed get_disc\n");
1606                 return ret;
1607         }
1608
1609         if (pkt_good_disc(pd, &di))
1610                 return -ENXIO;
1611
1612         switch (pd->mmc3_profile) {
1613                 case 0x1a: /* DVD+RW */
1614                         printk("pktcdvd: inserted media is DVD+RW\n");
1615                         break;
1616                 case 0x13: /* DVD-RW */
1617                         printk("pktcdvd: inserted media is DVD-RW\n");
1618                         break;
1619                 case 0x12: /* DVD-RAM */
1620                         printk("pktcdvd: inserted media is DVD-RAM\n");
1621                         break;
1622                 default:
1623                         printk("pktcdvd: inserted media is CD-R%s\n", di.erasable ? "W" : "");
1624                         break;
1625         }
1626         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1627
1628         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1629         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1630                 printk("pktcdvd: failed get_track\n");
1631                 return ret;
1632         }
1633
1634         if (pkt_good_track(&ti)) {
1635                 printk("pktcdvd: can't write to this track\n");
1636                 return -ENXIO;
1637         }
1638
1639         /*
1640          * we keep packet size in 512 byte units, makes it easier to
1641          * deal with request calculations.
1642          */
1643         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1644         if (pd->settings.size == 0) {
1645                 printk("pktcdvd: detected zero packet size!\n");
1646                 pd->settings.size = 128;
1647         }
1648         if (pd->settings.size > PACKET_MAX_SECTORS) {
1649                 printk("pktcdvd: packet size is too big\n");
1650                 return -ENXIO;
1651         }
1652         pd->settings.fp = ti.fp;
1653         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1654
1655         if (ti.nwa_v) {
1656                 pd->nwa = be32_to_cpu(ti.next_writable);
1657                 set_bit(PACKET_NWA_VALID, &pd->flags);
1658         }
1659
1660         /*
1661          * in theory we could use lra on -RW media as well and just zero
1662          * blocks that haven't been written yet, but in practice that
1663          * is just a no-go. we'll use that for -R, naturally.
1664          */
1665         if (ti.lra_v) {
1666                 pd->lra = be32_to_cpu(ti.last_rec_address);
1667                 set_bit(PACKET_LRA_VALID, &pd->flags);
1668         } else {
1669                 pd->lra = 0xffffffff;
1670                 set_bit(PACKET_LRA_VALID, &pd->flags);
1671         }
1672
1673         /*
1674          * fine for now
1675          */
1676         pd->settings.link_loss = 7;
1677         pd->settings.write_type = 0;    /* packet */
1678         pd->settings.track_mode = ti.track_mode;
1679
1680         /*
1681          * mode1 or mode2 disc
1682          */
1683         switch (ti.data_mode) {
1684                 case PACKET_MODE1:
1685                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1686                         break;
1687                 case PACKET_MODE2:
1688                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1689                         break;
1690                 default:
1691                         printk("pktcdvd: unknown data mode\n");
1692                         return 1;
1693         }
1694         return 0;
1695 }
1696
1697 /*
1698  * enable/disable write caching on drive
1699  */
1700 static int pkt_write_caching(struct pktcdvd_device *pd, int set)
1701 {
1702         struct packet_command cgc;
1703         struct request_sense sense;
1704         unsigned char buf[64];
1705         int ret;
1706
1707         memset(buf, 0, sizeof(buf));
1708         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1709         cgc.sense = &sense;
1710         cgc.buflen = pd->mode_offset + 12;
1711
1712         /*
1713          * caching mode page might not be there, so quiet this command
1714          */
1715         cgc.quiet = 1;
1716
1717         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
1718                 return ret;
1719
1720         buf[pd->mode_offset + 10] |= (!!set << 2);
1721
1722         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1723         ret = pkt_mode_select(pd, &cgc);
1724         if (ret) {
1725                 printk("pktcdvd: write caching control failed\n");
1726                 pkt_dump_sense(&cgc);
1727         } else if (!ret && set)
1728                 printk("pktcdvd: enabled write caching on %s\n", pd->name);
1729         return ret;
1730 }
1731
1732 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1733 {
1734         struct packet_command cgc;
1735
1736         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1737         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1738         cgc.cmd[4] = lockflag ? 1 : 0;
1739         return pkt_generic_packet(pd, &cgc);
1740 }
1741
1742 /*
1743  * Returns drive maximum write speed
1744  */
1745 static int pkt_get_max_speed(struct pktcdvd_device *pd, unsigned *write_speed)
1746 {
1747         struct packet_command cgc;
1748         struct request_sense sense;
1749         unsigned char buf[256+18];
1750         unsigned char *cap_buf;
1751         int ret, offset;
1752
1753         memset(buf, 0, sizeof(buf));
1754         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1755         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1756         cgc.sense = &sense;
1757
1758         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1759         if (ret) {
1760                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1761                              sizeof(struct mode_page_header);
1762                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1763                 if (ret) {
1764                         pkt_dump_sense(&cgc);
1765                         return ret;
1766                 }
1767         }
1768
1769         offset = 20;                        /* Obsoleted field, used by older drives */
1770         if (cap_buf[1] >= 28)
1771                 offset = 28;                /* Current write speed selected */
1772         if (cap_buf[1] >= 30) {
1773                 /* If the drive reports at least one "Logical Unit Write
1774                  * Speed Performance Descriptor Block", use the information
1775                  * in the first block. (contains the highest speed)
1776                  */
1777                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
1778                 if (num_spdb > 0)
1779                         offset = 34;
1780         }
1781
1782         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
1783         return 0;
1784 }
1785
1786 /* These tables from cdrecord - I don't have orange book */
1787 /* standard speed CD-RW (1-4x) */
1788 static char clv_to_speed[16] = {
1789         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1790            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1791 };
1792 /* high speed CD-RW (-10x) */
1793 static char hs_clv_to_speed[16] = {
1794         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1795            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
1796 };
1797 /* ultra high speed CD-RW */
1798 static char us_clv_to_speed[16] = {
1799         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
1800            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
1801 };
1802
1803 /*
1804  * reads the maximum media speed from ATIP
1805  */
1806 static int pkt_media_speed(struct pktcdvd_device *pd, unsigned *speed)
1807 {
1808         struct packet_command cgc;
1809         struct request_sense sense;
1810         unsigned char buf[64];
1811         unsigned int size, st, sp;
1812         int ret;
1813
1814         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
1815         cgc.sense = &sense;
1816         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
1817         cgc.cmd[1] = 2;
1818         cgc.cmd[2] = 4; /* READ ATIP */
1819         cgc.cmd[8] = 2;
1820         ret = pkt_generic_packet(pd, &cgc);
1821         if (ret) {
1822                 pkt_dump_sense(&cgc);
1823                 return ret;
1824         }
1825         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
1826         if (size > sizeof(buf))
1827                 size = sizeof(buf);
1828
1829         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
1830         cgc.sense = &sense;
1831         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
1832         cgc.cmd[1] = 2;
1833         cgc.cmd[2] = 4;
1834         cgc.cmd[8] = size;
1835         ret = pkt_generic_packet(pd, &cgc);
1836         if (ret) {
1837                 pkt_dump_sense(&cgc);
1838                 return ret;
1839         }
1840
1841         if (!buf[6] & 0x40) {
1842                 printk("pktcdvd: Disc type is not CD-RW\n");
1843                 return 1;
1844         }
1845         if (!buf[6] & 0x4) {
1846                 printk("pktcdvd: A1 values on media are not valid, maybe not CDRW?\n");
1847                 return 1;
1848         }
1849
1850         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
1851
1852         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
1853
1854         /* Info from cdrecord */
1855         switch (st) {
1856                 case 0: /* standard speed */
1857                         *speed = clv_to_speed[sp];
1858                         break;
1859                 case 1: /* high speed */
1860                         *speed = hs_clv_to_speed[sp];
1861                         break;
1862                 case 2: /* ultra high speed */
1863                         *speed = us_clv_to_speed[sp];
1864                         break;
1865                 default:
1866                         printk("pktcdvd: Unknown disc sub-type %d\n",st);
1867                         return 1;
1868         }
1869         if (*speed) {
1870                 printk("pktcdvd: Max. media speed: %d\n",*speed);
1871                 return 0;
1872         } else {
1873                 printk("pktcdvd: Unknown speed %d for sub-type %d\n",sp,st);
1874                 return 1;
1875         }
1876 }
1877
1878 static int pkt_perform_opc(struct pktcdvd_device *pd)
1879 {
1880         struct packet_command cgc;
1881         struct request_sense sense;
1882         int ret;
1883
1884         VPRINTK("pktcdvd: Performing OPC\n");
1885
1886         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1887         cgc.sense = &sense;
1888         cgc.timeout = 60*HZ;
1889         cgc.cmd[0] = GPCMD_SEND_OPC;
1890         cgc.cmd[1] = 1;
1891         if ((ret = pkt_generic_packet(pd, &cgc)))
1892                 pkt_dump_sense(&cgc);
1893         return ret;
1894 }
1895
1896 static int pkt_open_write(struct pktcdvd_device *pd)
1897 {
1898         int ret;
1899         unsigned int write_speed, media_write_speed, read_speed;
1900
1901         if ((ret = pkt_probe_settings(pd))) {
1902                 DPRINTK("pktcdvd: %s failed probe\n", pd->name);
1903                 return -EIO;
1904         }
1905
1906         if ((ret = pkt_set_write_settings(pd))) {
1907                 DPRINTK("pktcdvd: %s failed saving write settings\n", pd->name);
1908                 return -EIO;
1909         }
1910
1911         pkt_write_caching(pd, USE_WCACHING);
1912
1913         if ((ret = pkt_get_max_speed(pd, &write_speed)))
1914                 write_speed = 16 * 177;
1915         switch (pd->mmc3_profile) {
1916                 case 0x13: /* DVD-RW */
1917                 case 0x1a: /* DVD+RW */
1918                 case 0x12: /* DVD-RAM */
1919                         DPRINTK("pktcdvd: write speed %ukB/s\n", write_speed);
1920                         break;
1921                 default:
1922                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
1923                                 media_write_speed = 16;
1924                         write_speed = min(write_speed, media_write_speed * 177);
1925                         DPRINTK("pktcdvd: write speed %ux\n", write_speed / 176);
1926                         break;
1927         }
1928         read_speed = write_speed;
1929
1930         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
1931                 DPRINTK("pktcdvd: %s couldn't set write speed\n", pd->name);
1932                 return -EIO;
1933         }
1934         pd->write_speed = write_speed;
1935         pd->read_speed = read_speed;
1936
1937         if ((ret = pkt_perform_opc(pd))) {
1938                 DPRINTK("pktcdvd: %s Optimum Power Calibration failed\n", pd->name);
1939         }
1940
1941         return 0;
1942 }
1943
1944 /*
1945  * called at open time.
1946  */
1947 static int pkt_open_dev(struct pktcdvd_device *pd, int write)
1948 {
1949         int ret;
1950         long lba;
1951         request_queue_t *q;
1952
1953         /*
1954          * We need to re-open the cdrom device without O_NONBLOCK to be able
1955          * to read/write from/to it. It is already opened in O_NONBLOCK mode
1956          * so bdget() can't fail.
1957          */
1958         bdget(pd->bdev->bd_dev);
1959         if ((ret = blkdev_get(pd->bdev, FMODE_READ, O_RDONLY)))
1960                 goto out;
1961
1962         if ((ret = pkt_get_last_written(pd, &lba))) {
1963                 printk("pktcdvd: pkt_get_last_written failed\n");
1964                 goto out_putdev;
1965         }
1966
1967         set_capacity(pd->disk, lba << 2);
1968         set_capacity(pd->bdev->bd_disk, lba << 2);
1969         bd_set_size(pd->bdev, (loff_t)lba << 11);
1970
1971         q = bdev_get_queue(pd->bdev);
1972         if (write) {
1973                 if ((ret = pkt_open_write(pd)))
1974                         goto out_putdev;
1975                 /*
1976                  * Some CDRW drives can not handle writes larger than one packet,
1977                  * even if the size is a multiple of the packet size.
1978                  */
1979                 spin_lock_irq(q->queue_lock);
1980                 blk_queue_max_sectors(q, pd->settings.size);
1981                 spin_unlock_irq(q->queue_lock);
1982                 set_bit(PACKET_WRITABLE, &pd->flags);
1983         } else {
1984                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
1985                 clear_bit(PACKET_WRITABLE, &pd->flags);
1986         }
1987
1988         if ((ret = pkt_set_segment_merging(pd, q)))
1989                 goto out_putdev;
1990
1991         if (write)
1992                 printk("pktcdvd: %lukB available on disc\n", lba << 1);
1993
1994         return 0;
1995
1996 out_putdev:
1997         blkdev_put(pd->bdev);
1998 out:
1999         return ret;
2000 }
2001
2002 /*
2003  * called when the device is closed. makes sure that the device flushes
2004  * the internal cache before we close.
2005  */
2006 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2007 {
2008         if (flush && pkt_flush_cache(pd))
2009                 DPRINTK("pktcdvd: %s not flushing cache\n", pd->name);
2010
2011         pkt_lock_door(pd, 0);
2012
2013         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2014         blkdev_put(pd->bdev);
2015 }
2016
2017 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
2018 {
2019         if (dev_minor >= MAX_WRITERS)
2020                 return NULL;
2021         return pkt_devs[dev_minor];
2022 }
2023
2024 static int pkt_open(struct inode *inode, struct file *file)
2025 {
2026         struct pktcdvd_device *pd = NULL;
2027         int ret;
2028
2029         VPRINTK("pktcdvd: entering open\n");
2030
2031         down(&ctl_mutex);
2032         pd = pkt_find_dev_from_minor(iminor(inode));
2033         if (!pd) {
2034                 ret = -ENODEV;
2035                 goto out;
2036         }
2037         BUG_ON(pd->refcnt < 0);
2038
2039         pd->refcnt++;
2040         if (pd->refcnt > 1) {
2041                 if ((file->f_mode & FMODE_WRITE) &&
2042                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2043                         ret = -EBUSY;
2044                         goto out_dec;
2045                 }
2046         } else {
2047                 if (pkt_open_dev(pd, file->f_mode & FMODE_WRITE)) {
2048                         ret = -EIO;
2049                         goto out_dec;
2050                 }
2051                 /*
2052                  * needed here as well, since ext2 (among others) may change
2053                  * the blocksize at mount time
2054                  */
2055                 set_blocksize(inode->i_bdev, CD_FRAMESIZE);
2056         }
2057
2058         up(&ctl_mutex);
2059         return 0;
2060
2061 out_dec:
2062         pd->refcnt--;
2063 out:
2064         VPRINTK("pktcdvd: failed open (%d)\n", ret);
2065         up(&ctl_mutex);
2066         return ret;
2067 }
2068
2069 static int pkt_close(struct inode *inode, struct file *file)
2070 {
2071         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2072         int ret = 0;
2073
2074         down(&ctl_mutex);
2075         pd->refcnt--;
2076         BUG_ON(pd->refcnt < 0);
2077         if (pd->refcnt == 0) {
2078                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2079                 pkt_release_dev(pd, flush);
2080         }
2081         up(&ctl_mutex);
2082         return ret;
2083 }
2084
2085
2086 static void *psd_pool_alloc(unsigned int __nocast gfp_mask, void *data)
2087 {
2088         return kmalloc(sizeof(struct packet_stacked_data), gfp_mask);
2089 }
2090
2091 static void psd_pool_free(void *ptr, void *data)
2092 {
2093         kfree(ptr);
2094 }
2095
2096 static int pkt_end_io_read_cloned(struct bio *bio, unsigned int bytes_done, int err)
2097 {
2098         struct packet_stacked_data *psd = bio->bi_private;
2099         struct pktcdvd_device *pd = psd->pd;
2100
2101         if (bio->bi_size)
2102                 return 1;
2103
2104         bio_put(bio);
2105         bio_endio(psd->bio, psd->bio->bi_size, err);
2106         mempool_free(psd, psd_pool);
2107         pkt_bio_finished(pd);
2108         return 0;
2109 }
2110
2111 static int pkt_make_request(request_queue_t *q, struct bio *bio)
2112 {
2113         struct pktcdvd_device *pd;
2114         char b[BDEVNAME_SIZE];
2115         sector_t zone;
2116         struct packet_data *pkt;
2117         int was_empty, blocked_bio;
2118         struct pkt_rb_node *node;
2119
2120         pd = q->queuedata;
2121         if (!pd) {
2122                 printk("pktcdvd: %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
2123                 goto end_io;
2124         }
2125
2126         /*
2127          * Clone READ bios so we can have our own bi_end_io callback.
2128          */
2129         if (bio_data_dir(bio) == READ) {
2130                 struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2131                 struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2132
2133                 psd->pd = pd;
2134                 psd->bio = bio;
2135                 cloned_bio->bi_bdev = pd->bdev;
2136                 cloned_bio->bi_private = psd;
2137                 cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2138                 pd->stats.secs_r += bio->bi_size >> 9;
2139                 pkt_queue_bio(pd, cloned_bio);
2140                 return 0;
2141         }
2142
2143         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2144                 printk("pktcdvd: WRITE for ro device %s (%llu)\n",
2145                         pd->name, (unsigned long long)bio->bi_sector);
2146                 goto end_io;
2147         }
2148
2149         if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
2150                 printk("pktcdvd: wrong bio size\n");
2151                 goto end_io;
2152         }
2153
2154         blk_queue_bounce(q, &bio);
2155
2156         zone = ZONE(bio->bi_sector, pd);
2157         VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
2158                 (unsigned long long)bio->bi_sector,
2159                 (unsigned long long)(bio->bi_sector + bio_sectors(bio)));
2160
2161         /* Check if we have to split the bio */
2162         {
2163                 struct bio_pair *bp;
2164                 sector_t last_zone;
2165                 int first_sectors;
2166
2167                 last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
2168                 if (last_zone != zone) {
2169                         BUG_ON(last_zone != zone + pd->settings.size);
2170                         first_sectors = last_zone - bio->bi_sector;
2171                         bp = bio_split(bio, bio_split_pool, first_sectors);
2172                         BUG_ON(!bp);
2173                         pkt_make_request(q, &bp->bio1);
2174                         pkt_make_request(q, &bp->bio2);
2175                         bio_pair_release(bp);
2176                         return 0;
2177                 }
2178         }
2179
2180         /*
2181          * If we find a matching packet in state WAITING or READ_WAIT, we can
2182          * just append this bio to that packet.
2183          */
2184         spin_lock(&pd->cdrw.active_list_lock);
2185         blocked_bio = 0;
2186         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2187                 if (pkt->sector == zone) {
2188                         spin_lock(&pkt->lock);
2189                         if ((pkt->state == PACKET_WAITING_STATE) ||
2190                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2191                                 pkt_add_list_last(bio, &pkt->orig_bios,
2192                                                   &pkt->orig_bios_tail);
2193                                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
2194                                 if ((pkt->write_size >= pkt->frames) &&
2195                                     (pkt->state == PACKET_WAITING_STATE)) {
2196                                         atomic_inc(&pkt->run_sm);
2197                                         wake_up(&pd->wqueue);
2198                                 }
2199                                 spin_unlock(&pkt->lock);
2200                                 spin_unlock(&pd->cdrw.active_list_lock);
2201                                 return 0;
2202                         } else {
2203                                 blocked_bio = 1;
2204                         }
2205                         spin_unlock(&pkt->lock);
2206                 }
2207         }
2208         spin_unlock(&pd->cdrw.active_list_lock);
2209
2210         /*
2211          * No matching packet found. Store the bio in the work queue.
2212          */
2213         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2214         BUG_ON(!node);
2215         node->bio = bio;
2216         spin_lock(&pd->lock);
2217         BUG_ON(pd->bio_queue_size < 0);
2218         was_empty = (pd->bio_queue_size == 0);
2219         pkt_rbtree_insert(pd, node);
2220         spin_unlock(&pd->lock);
2221
2222         /*
2223          * Wake up the worker thread.
2224          */
2225         atomic_set(&pd->scan_queue, 1);
2226         if (was_empty) {
2227                 /* This wake_up is required for correct operation */
2228                 wake_up(&pd->wqueue);
2229         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2230                 /*
2231                  * This wake up is not required for correct operation,
2232                  * but improves performance in some cases.
2233                  */
2234                 wake_up(&pd->wqueue);
2235         }
2236         return 0;
2237 end_io:
2238         bio_io_error(bio, bio->bi_size);
2239         return 0;
2240 }
2241
2242
2243
2244 static int pkt_merge_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *bvec)
2245 {
2246         struct pktcdvd_device *pd = q->queuedata;
2247         sector_t zone = ZONE(bio->bi_sector, pd);
2248         int used = ((bio->bi_sector - zone) << 9) + bio->bi_size;
2249         int remaining = (pd->settings.size << 9) - used;
2250         int remaining2;
2251
2252         /*
2253          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2254          * boundary, pkt_make_request() will split the bio.
2255          */
2256         remaining2 = PAGE_SIZE - bio->bi_size;
2257         remaining = max(remaining, remaining2);
2258
2259         BUG_ON(remaining < 0);
2260         return remaining;
2261 }
2262
2263 static void pkt_init_queue(struct pktcdvd_device *pd)
2264 {
2265         request_queue_t *q = pd->disk->queue;
2266
2267         blk_queue_make_request(q, pkt_make_request);
2268         blk_queue_hardsect_size(q, CD_FRAMESIZE);
2269         blk_queue_max_sectors(q, PACKET_MAX_SECTORS);
2270         blk_queue_merge_bvec(q, pkt_merge_bvec);
2271         q->queuedata = pd;
2272 }
2273
2274 static int pkt_seq_show(struct seq_file *m, void *p)
2275 {
2276         struct pktcdvd_device *pd = m->private;
2277         char *msg;
2278         char bdev_buf[BDEVNAME_SIZE];
2279         int states[PACKET_NUM_STATES];
2280
2281         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2282                    bdevname(pd->bdev, bdev_buf));
2283
2284         seq_printf(m, "\nSettings:\n");
2285         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2286
2287         if (pd->settings.write_type == 0)
2288                 msg = "Packet";
2289         else
2290                 msg = "Unknown";
2291         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2292
2293         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2294         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2295
2296         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2297
2298         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2299                 msg = "Mode 1";
2300         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2301                 msg = "Mode 2";
2302         else
2303                 msg = "Unknown";
2304         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2305
2306         seq_printf(m, "\nStatistics:\n");
2307         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2308         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2309         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2310         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2311         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2312
2313         seq_printf(m, "\nMisc:\n");
2314         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2315         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2316         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2317         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2318         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2319         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2320
2321         seq_printf(m, "\nQueue state:\n");
2322         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2323         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2324         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2325
2326         pkt_count_states(pd, states);
2327         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2328                    states[0], states[1], states[2], states[3], states[4], states[5]);
2329
2330         return 0;
2331 }
2332
2333 static int pkt_seq_open(struct inode *inode, struct file *file)
2334 {
2335         return single_open(file, pkt_seq_show, PDE(inode)->data);
2336 }
2337
2338 static struct file_operations pkt_proc_fops = {
2339         .open   = pkt_seq_open,
2340         .read   = seq_read,
2341         .llseek = seq_lseek,
2342         .release = single_release
2343 };
2344
2345 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2346 {
2347         int i;
2348         int ret = 0;
2349         char b[BDEVNAME_SIZE];
2350         struct proc_dir_entry *proc;
2351         struct block_device *bdev;
2352
2353         if (pd->pkt_dev == dev) {
2354                 printk("pktcdvd: Recursive setup not allowed\n");
2355                 return -EBUSY;
2356         }
2357         for (i = 0; i < MAX_WRITERS; i++) {
2358                 struct pktcdvd_device *pd2 = pkt_devs[i];
2359                 if (!pd2)
2360                         continue;
2361                 if (pd2->bdev->bd_dev == dev) {
2362                         printk("pktcdvd: %s already setup\n", bdevname(pd2->bdev, b));
2363                         return -EBUSY;
2364                 }
2365                 if (pd2->pkt_dev == dev) {
2366                         printk("pktcdvd: Can't chain pktcdvd devices\n");
2367                         return -EBUSY;
2368                 }
2369         }
2370
2371         bdev = bdget(dev);
2372         if (!bdev)
2373                 return -ENOMEM;
2374         ret = blkdev_get(bdev, FMODE_READ, O_RDONLY | O_NONBLOCK);
2375         if (ret)
2376                 return ret;
2377
2378         /* This is safe, since we have a reference from open(). */
2379         __module_get(THIS_MODULE);
2380
2381         if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2382                 printk("pktcdvd: not enough memory for buffers\n");
2383                 ret = -ENOMEM;
2384                 goto out_mem;
2385         }
2386
2387         pd->bdev = bdev;
2388         set_blocksize(bdev, CD_FRAMESIZE);
2389
2390         pkt_init_queue(pd);
2391
2392         atomic_set(&pd->cdrw.pending_bios, 0);
2393         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2394         if (IS_ERR(pd->cdrw.thread)) {
2395                 printk("pktcdvd: can't start kernel thread\n");
2396                 ret = -ENOMEM;
2397                 goto out_thread;
2398         }
2399
2400         proc = create_proc_entry(pd->name, 0, pkt_proc);
2401         if (proc) {
2402                 proc->data = pd;
2403                 proc->proc_fops = &pkt_proc_fops;
2404         }
2405         DPRINTK("pktcdvd: writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
2406         return 0;
2407
2408 out_thread:
2409         pkt_shrink_pktlist(pd);
2410 out_mem:
2411         blkdev_put(bdev);
2412         /* This is safe: open() is still holding a reference. */
2413         module_put(THIS_MODULE);
2414         return ret;
2415 }
2416
2417 static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
2418 {
2419         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2420
2421         VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd, imajor(inode), iminor(inode));
2422         BUG_ON(!pd);
2423
2424         switch (cmd) {
2425         /*
2426          * forward selected CDROM ioctls to CD-ROM, for UDF
2427          */
2428         case CDROMMULTISESSION:
2429         case CDROMREADTOCENTRY:
2430         case CDROM_LAST_WRITTEN:
2431         case CDROM_SEND_PACKET:
2432         case SCSI_IOCTL_SEND_COMMAND:
2433                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2434
2435         case CDROMEJECT:
2436                 /*
2437                  * The door gets locked when the device is opened, so we
2438                  * have to unlock it or else the eject command fails.
2439                  */
2440                 pkt_lock_door(pd, 0);
2441                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2442
2443         default:
2444                 printk("pktcdvd: Unknown ioctl for %s (%x)\n", pd->name, cmd);
2445                 return -ENOTTY;
2446         }
2447
2448         return 0;
2449 }
2450
2451 static int pkt_media_changed(struct gendisk *disk)
2452 {
2453         struct pktcdvd_device *pd = disk->private_data;
2454         struct gendisk *attached_disk;
2455
2456         if (!pd)
2457                 return 0;
2458         if (!pd->bdev)
2459                 return 0;
2460         attached_disk = pd->bdev->bd_disk;
2461         if (!attached_disk)
2462                 return 0;
2463         return attached_disk->fops->media_changed(attached_disk);
2464 }
2465
2466 static struct block_device_operations pktcdvd_ops = {
2467         .owner =                THIS_MODULE,
2468         .open =                 pkt_open,
2469         .release =              pkt_close,
2470         .ioctl =                pkt_ioctl,
2471         .media_changed =        pkt_media_changed,
2472 };
2473
2474 /*
2475  * Set up mapping from pktcdvd device to CD-ROM device.
2476  */
2477 static int pkt_setup_dev(struct pkt_ctrl_command *ctrl_cmd)
2478 {
2479         int idx;
2480         int ret = -ENOMEM;
2481         struct pktcdvd_device *pd;
2482         struct gendisk *disk;
2483         dev_t dev = new_decode_dev(ctrl_cmd->dev);
2484
2485         for (idx = 0; idx < MAX_WRITERS; idx++)
2486                 if (!pkt_devs[idx])
2487                         break;
2488         if (idx == MAX_WRITERS) {
2489                 printk("pktcdvd: max %d writers supported\n", MAX_WRITERS);
2490                 return -EBUSY;
2491         }
2492
2493         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2494         if (!pd)
2495                 return ret;
2496
2497         pd->rb_pool = mempool_create(PKT_RB_POOL_SIZE, pkt_rb_alloc, pkt_rb_free, NULL);
2498         if (!pd->rb_pool)
2499                 goto out_mem;
2500
2501         disk = alloc_disk(1);
2502         if (!disk)
2503                 goto out_mem;
2504         pd->disk = disk;
2505
2506         spin_lock_init(&pd->lock);
2507         spin_lock_init(&pd->iosched.lock);
2508         sprintf(pd->name, "pktcdvd%d", idx);
2509         init_waitqueue_head(&pd->wqueue);
2510         pd->bio_queue = RB_ROOT;
2511
2512         disk->major = pkt_major;
2513         disk->first_minor = idx;
2514         disk->fops = &pktcdvd_ops;
2515         disk->flags = GENHD_FL_REMOVABLE;
2516         sprintf(disk->disk_name, "pktcdvd%d", idx);
2517         disk->private_data = pd;
2518         disk->queue = blk_alloc_queue(GFP_KERNEL);
2519         if (!disk->queue)
2520                 goto out_mem2;
2521
2522         pd->pkt_dev = MKDEV(disk->major, disk->first_minor);
2523         ret = pkt_new_dev(pd, dev);
2524         if (ret)
2525                 goto out_new_dev;
2526
2527         add_disk(disk);
2528         pkt_devs[idx] = pd;
2529         ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2530         return 0;
2531
2532 out_new_dev:
2533         blk_put_queue(disk->queue);
2534 out_mem2:
2535         put_disk(disk);
2536 out_mem:
2537         if (pd->rb_pool)
2538                 mempool_destroy(pd->rb_pool);
2539         kfree(pd);
2540         return ret;
2541 }
2542
2543 /*
2544  * Tear down mapping from pktcdvd device to CD-ROM device.
2545  */
2546 static int pkt_remove_dev(struct pkt_ctrl_command *ctrl_cmd)
2547 {
2548         struct pktcdvd_device *pd;
2549         int idx;
2550         dev_t pkt_dev = new_decode_dev(ctrl_cmd->pkt_dev);
2551
2552         for (idx = 0; idx < MAX_WRITERS; idx++) {
2553                 pd = pkt_devs[idx];
2554                 if (pd && (pd->pkt_dev == pkt_dev))
2555                         break;
2556         }
2557         if (idx == MAX_WRITERS) {
2558                 DPRINTK("pktcdvd: dev not setup\n");
2559                 return -ENXIO;
2560         }
2561
2562         if (pd->refcnt > 0)
2563                 return -EBUSY;
2564
2565         if (!IS_ERR(pd->cdrw.thread))
2566                 kthread_stop(pd->cdrw.thread);
2567
2568         blkdev_put(pd->bdev);
2569
2570         pkt_shrink_pktlist(pd);
2571
2572         remove_proc_entry(pd->name, pkt_proc);
2573         DPRINTK("pktcdvd: writer %s unmapped\n", pd->name);
2574
2575         del_gendisk(pd->disk);
2576         blk_put_queue(pd->disk->queue);
2577         put_disk(pd->disk);
2578
2579         pkt_devs[idx] = NULL;
2580         mempool_destroy(pd->rb_pool);
2581         kfree(pd);
2582
2583         /* This is safe: open() is still holding a reference. */
2584         module_put(THIS_MODULE);
2585         return 0;
2586 }
2587
2588 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2589 {
2590         struct pktcdvd_device *pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2591         if (pd) {
2592                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2593                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2594         } else {
2595                 ctrl_cmd->dev = 0;
2596                 ctrl_cmd->pkt_dev = 0;
2597         }
2598         ctrl_cmd->num_devices = MAX_WRITERS;
2599 }
2600
2601 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
2602 {
2603         void __user *argp = (void __user *)arg;
2604         struct pkt_ctrl_command ctrl_cmd;
2605         int ret = 0;
2606
2607         if (cmd != PACKET_CTRL_CMD)
2608                 return -ENOTTY;
2609
2610         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2611                 return -EFAULT;
2612
2613         switch (ctrl_cmd.command) {
2614         case PKT_CTRL_CMD_SETUP:
2615                 if (!capable(CAP_SYS_ADMIN))
2616                         return -EPERM;
2617                 down(&ctl_mutex);
2618                 ret = pkt_setup_dev(&ctrl_cmd);
2619                 up(&ctl_mutex);
2620                 break;
2621         case PKT_CTRL_CMD_TEARDOWN:
2622                 if (!capable(CAP_SYS_ADMIN))
2623                         return -EPERM;
2624                 down(&ctl_mutex);
2625                 ret = pkt_remove_dev(&ctrl_cmd);
2626                 up(&ctl_mutex);
2627                 break;
2628         case PKT_CTRL_CMD_STATUS:
2629                 down(&ctl_mutex);
2630                 pkt_get_status(&ctrl_cmd);
2631                 up(&ctl_mutex);
2632                 break;
2633         default:
2634                 return -ENOTTY;
2635         }
2636
2637         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2638                 return -EFAULT;
2639         return ret;
2640 }
2641
2642
2643 static struct file_operations pkt_ctl_fops = {
2644         .ioctl   = pkt_ctl_ioctl,
2645         .owner   = THIS_MODULE,
2646 };
2647
2648 static struct miscdevice pkt_misc = {
2649         .minor          = MISC_DYNAMIC_MINOR,
2650         .name           = "pktcdvd",
2651         .devfs_name     = "pktcdvd/control",
2652         .fops           = &pkt_ctl_fops
2653 };
2654
2655 static int __init pkt_init(void)
2656 {
2657         int ret;
2658
2659         psd_pool = mempool_create(PSD_POOL_SIZE, psd_pool_alloc, psd_pool_free, NULL);
2660         if (!psd_pool)
2661                 return -ENOMEM;
2662
2663         ret = register_blkdev(pkt_major, "pktcdvd");
2664         if (ret < 0) {
2665                 printk("pktcdvd: Unable to register block device\n");
2666                 goto out2;
2667         }
2668         if (!pkt_major)
2669                 pkt_major = ret;
2670
2671         ret = misc_register(&pkt_misc);
2672         if (ret) {
2673                 printk("pktcdvd: Unable to register misc device\n");
2674                 goto out;
2675         }
2676
2677         init_MUTEX(&ctl_mutex);
2678
2679         pkt_proc = proc_mkdir("pktcdvd", proc_root_driver);
2680
2681         DPRINTK("pktcdvd: %s\n", VERSION_CODE);
2682         return 0;
2683
2684 out:
2685         unregister_blkdev(pkt_major, "pktcdvd");
2686 out2:
2687         mempool_destroy(psd_pool);
2688         return ret;
2689 }
2690
2691 static void __exit pkt_exit(void)
2692 {
2693         remove_proc_entry("pktcdvd", proc_root_driver);
2694         misc_deregister(&pkt_misc);
2695         unregister_blkdev(pkt_major, "pktcdvd");
2696         mempool_destroy(psd_pool);
2697 }
2698
2699 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
2700 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
2701 MODULE_LICENSE("GPL");
2702
2703 module_init(pkt_init);
2704 module_exit(pkt_exit);