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