drivers/block/pktcdvd.c

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