git.oblomov.eu Git - linux-2.6/blob - drivers/block/pktcdvd.c

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