drivers/block/pktcdvd.c

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