drivers/block/pktcdvd.c

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