drivers/block/pktcdvd.c

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <[email protected]>
   3  * Copyright (C) 2001-2004 Peter Osterlund <[email protected]>
   4  * Copyright (C) 2006 Thomas Maier <[email protected]>
   5  *
   6  * May be copied or modified under the terms of the GNU General Public
   7  * License.  See linux/COPYING for more information.
   8  *
   9  * Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
  10  * DVD-RAM devices.
  11  *
  12  * Theory of operation:
  13  *
  14  * At the lowest level, there is the standard driver for the CD/DVD device,
  15  * typically ide-cd.c or sr.c. This driver can handle read and write requests,
  16  * but it doesn't know anything about the special restrictions that apply to
  17  * packet writing. One restriction is that write requests must be aligned to
  18  * packet boundaries on the physical media, and the size of a write request
  19  * must be equal to the packet size. Another restriction is that a
  20  * GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
  21  * command, if the previous command was a write.
  22  *
  23  * The purpose of the packet writing driver is to hide these restrictions from
  24  * higher layers, such as file systems, and present a block device that can be
  25  * randomly read and written using 2kB-sized blocks.
  26  *
  27  * The lowest layer in the packet writing driver is the packet I/O scheduler.
  28  * Its data is defined by the struct packet_iosched and includes two bio
  29  * queues with pending read and write requests. These queues are processed
  30  * by the pkt_iosched_process_queue() function. The write requests in this
  31  * queue are already properly aligned and sized. This layer is responsible for
  32  * issuing the flush cache commands and scheduling the I/O in a good order.
  33  *
  34  * The next layer transforms unaligned write requests to aligned writes. This
  35  * transformation requires reading missing pieces of data from the underlying
  36  * block device, assembling the pieces to full packets and queuing them to the
  37  * packet I/O scheduler.
  38  *
  39  * At the top layer there is a custom make_request_fn function that forwards
  40  * read requests directly to the iosched queue and puts write requests in the
  41  * unaligned write queue. A kernel thread performs the necessary read
  42  * gathering to convert the unaligned writes to aligned writes and then feeds
  43  * them to the packet I/O scheduler.
  44  *
  45  *************************************************************************/
  46
  47 #include <linux/pktcdvd.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/freezer.h>
  59 #include <linux/mutex.h>
  60 #include <scsi/scsi_cmnd.h>
  61 #include <scsi/scsi_ioctl.h>
  62 #include <scsi/scsi.h>
  63 #include <linux/debugfs.h>
  64 #include <linux/device.h>
  65
  66 #include <asm/uaccess.h>
  67
  68 #define DRIVER_NAME     "pktcdvd"
  69
  70 #if PACKET_DEBUG
  71 #define DPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
  72 #else
  73 #define DPRINTK(fmt, args...)
  74 #endif
  75
  76 #if PACKET_DEBUG > 1
  77 #define VPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
  78 #else
  79 #define VPRINTK(fmt, args...)
  80 #endif
  81
  82 #define MAX_SPEED 0xffff
  83
  84 #define ZONE(sector, pd) (((sector) + (pd)->offset) & ~((pd)->settings.size - 1))
  85
  86 static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
  87 static struct proc_dir_entry *pkt_proc;
  88 static int pktdev_major;
  89 static int write_congestion_on  = PKT_WRITE_CONGESTION_ON;
  90 static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
  91 static struct mutex ctl_mutex;  /* Serialize open/close/setup/teardown */
  92 static mempool_t *psd_pool;
  93
  94 static struct class     *class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
  95 static struct dentry    *pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */
  96
  97 /* forward declaration */
  98 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
  99 static int pkt_remove_dev(dev_t pkt_dev);
 100 static int pkt_seq_show(struct seq_file *m, void *p);
 101
 102
 103
 104 /*
 105  * create and register a pktcdvd kernel object.
 106  */
 107 static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
 108                                         const char* name,
 109                                         struct kobject* parent,
 110                                         struct kobj_type* ktype)
 111 {
 112         struct pktcdvd_kobj *p;
 113         int error;
 114
 115         p = kzalloc(sizeof(*p), GFP_KERNEL);
 116         if (!p)
 117                 return NULL;
 118         p->pd = pd;
 119         error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
 120         if (error) {
 121                 kobject_put(&p->kobj);
 122                 return NULL;
 123         }
 124         kobject_uevent(&p->kobj, KOBJ_ADD);
 125         return p;
 126 }
 127 /*
 128  * remove a pktcdvd kernel object.
 129  */
 130 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
 131 {
 132         if (p)
 133                 kobject_put(&p->kobj);
 134 }
 135 /*
 136  * default release function for pktcdvd kernel objects.
 137  */
 138 static void pkt_kobj_release(struct kobject *kobj)
 139 {
 140         kfree(to_pktcdvdkobj(kobj));
 141 }
 142
 143
 144 /**********************************************************
 145  *
 146  * sysfs interface for pktcdvd
 147  * by (C) 2006  Thomas Maier <[email protected]>
 148  *
 149  **********************************************************/
 150
 151 #define DEF_ATTR(_obj,_name,_mode) \
 152         static struct attribute _obj = { .name = _name, .mode = _mode }
 153
 154 /**********************************************************
 155   /sys/class/pktcdvd/pktcdvd[0-7]/
 156                      stat/reset
 157                      stat/packets_started
 158                      stat/packets_finished
 159                      stat/kb_written
 160                      stat/kb_read
 161                      stat/kb_read_gather
 162                      write_queue/size
 163                      write_queue/congestion_off
 164                      write_queue/congestion_on
 165  **********************************************************/
 166
 167 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
 168 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
 169 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
 170 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
 171 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
 172 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
 173
 174 static struct attribute *kobj_pkt_attrs_stat[] = {
 175         &kobj_pkt_attr_st1,
 176         &kobj_pkt_attr_st2,
 177         &kobj_pkt_attr_st3,
 178         &kobj_pkt_attr_st4,
 179         &kobj_pkt_attr_st5,
 180         &kobj_pkt_attr_st6,
 181         NULL
 182 };
 183
 184 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
 185 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
 186 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
 187
 188 static struct attribute *kobj_pkt_attrs_wqueue[] = {
 189         &kobj_pkt_attr_wq1,
 190         &kobj_pkt_attr_wq2,
 191         &kobj_pkt_attr_wq3,
 192         NULL
 193 };
 194
 195 static ssize_t kobj_pkt_show(struct kobject *kobj,
 196                         struct attribute *attr, char *data)
 197 {
 198         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 199         int n = 0;
 200         int v;
 201         if (strcmp(attr->name, "packets_started") == 0) {
 202                 n = sprintf(data, "%lu\n", pd->stats.pkt_started);
 203
 204         } else if (strcmp(attr->name, "packets_finished") == 0) {
 205                 n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
 206
 207         } else if (strcmp(attr->name, "kb_written") == 0) {
 208                 n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
 209
 210         } else if (strcmp(attr->name, "kb_read") == 0) {
 211                 n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
 212
 213         } else if (strcmp(attr->name, "kb_read_gather") == 0) {
 214                 n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
 215
 216         } else if (strcmp(attr->name, "size") == 0) {
 217                 spin_lock(&pd->lock);
 218                 v = pd->bio_queue_size;
 219                 spin_unlock(&pd->lock);
 220                 n = sprintf(data, "%d\n", v);
 221
 222         } else if (strcmp(attr->name, "congestion_off") == 0) {
 223                 spin_lock(&pd->lock);
 224                 v = pd->write_congestion_off;
 225                 spin_unlock(&pd->lock);
 226                 n = sprintf(data, "%d\n", v);
 227
 228         } else if (strcmp(attr->name, "congestion_on") == 0) {
 229                 spin_lock(&pd->lock);
 230                 v = pd->write_congestion_on;
 231                 spin_unlock(&pd->lock);
 232                 n = sprintf(data, "%d\n", v);
 233         }
 234         return n;
 235 }
 236
 237 static void init_write_congestion_marks(int* lo, int* hi)
 238 {
 239         if (*hi > 0) {
 240                 *hi = max(*hi, 500);
 241                 *hi = min(*hi, 1000000);
 242                 if (*lo <= 0)
 243                         *lo = *hi - 100;
 244                 else {
 245                         *lo = min(*lo, *hi - 100);
 246                         *lo = max(*lo, 100);
 247                 }
 248         } else {
 249                 *hi = -1;
 250                 *lo = -1;
 251         }
 252 }
 253
 254 static ssize_t kobj_pkt_store(struct kobject *kobj,
 255                         struct attribute *attr,
 256                         const char *data, size_t len)
 257 {
 258         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 259         int val;
 260
 261         if (strcmp(attr->name, "reset") == 0 && len > 0) {
 262                 pd->stats.pkt_started = 0;
 263                 pd->stats.pkt_ended = 0;
 264                 pd->stats.secs_w = 0;
 265                 pd->stats.secs_rg = 0;
 266                 pd->stats.secs_r = 0;
 267
 268         } else if (strcmp(attr->name, "congestion_off") == 0
 269                    && sscanf(data, "%d", &val) == 1) {
 270                 spin_lock(&pd->lock);
 271                 pd->write_congestion_off = val;
 272                 init_write_congestion_marks(&pd->write_congestion_off,
 273                                         &pd->write_congestion_on);
 274                 spin_unlock(&pd->lock);
 275
 276         } else if (strcmp(attr->name, "congestion_on") == 0
 277                    && sscanf(data, "%d", &val) == 1) {
 278                 spin_lock(&pd->lock);
 279                 pd->write_congestion_on = val;
 280                 init_write_congestion_marks(&pd->write_congestion_off,
 281                                         &pd->write_congestion_on);
 282                 spin_unlock(&pd->lock);
 283         }
 284         return len;
 285 }
 286
 287 static struct sysfs_ops kobj_pkt_ops = {
 288         .show = kobj_pkt_show,
 289         .store = kobj_pkt_store
 290 };
 291 static struct kobj_type kobj_pkt_type_stat = {
 292         .release = pkt_kobj_release,
 293         .sysfs_ops = &kobj_pkt_ops,
 294         .default_attrs = kobj_pkt_attrs_stat
 295 };
 296 static struct kobj_type kobj_pkt_type_wqueue = {
 297         .release = pkt_kobj_release,
 298         .sysfs_ops = &kobj_pkt_ops,
 299         .default_attrs = kobj_pkt_attrs_wqueue
 300 };
 301
 302 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 303 {
 304         if (class_pktcdvd) {
 305                 pd->dev = device_create(class_pktcdvd, NULL, MKDEV(0, 0), NULL,
 306                                         "%s", pd->name);
 307                 if (IS_ERR(pd->dev))
 308                         pd->dev = NULL;
 309         }
 310         if (pd->dev) {
 311                 pd->kobj_stat = pkt_kobj_create(pd, "stat",
 312                                         &pd->dev->kobj,
 313                                         &kobj_pkt_type_stat);
 314                 pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
 315                                         &pd->dev->kobj,
 316                                         &kobj_pkt_type_wqueue);
 317         }
 318 }
 319
 320 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 321 {
 322         pkt_kobj_remove(pd->kobj_stat);
 323         pkt_kobj_remove(pd->kobj_wqueue);
 324         if (class_pktcdvd)
 325                 device_unregister(pd->dev);
 326 }
 327
 328
 329 /********************************************************************
 330   /sys/class/pktcdvd/
 331                      add            map block device
 332                      remove         unmap packet dev
 333                      device_map     show mappings
 334  *******************************************************************/
 335
 336 static void class_pktcdvd_release(struct class *cls)
 337 {
 338         kfree(cls);
 339 }
 340 static ssize_t class_pktcdvd_show_map(struct class *c, char *data)
 341 {
 342         int n = 0;
 343         int idx;
 344         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 345         for (idx = 0; idx < MAX_WRITERS; idx++) {
 346                 struct pktcdvd_device *pd = pkt_devs[idx];
 347                 if (!pd)
 348                         continue;
 349                 n += sprintf(data+n, "%s %u:%u %u:%u\n",
 350                         pd->name,
 351                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 352                         MAJOR(pd->bdev->bd_dev),
 353                         MINOR(pd->bdev->bd_dev));
 354         }
 355         mutex_unlock(&ctl_mutex);
 356         return n;
 357 }
 358
 359 static ssize_t class_pktcdvd_store_add(struct class *c, const char *buf,
 360                                         size_t count)
 361 {
 362         unsigned int major, minor;
 363
 364         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 365                 /* pkt_setup_dev() expects caller to hold reference to self */
 366                 if (!try_module_get(THIS_MODULE))
 367                         return -ENODEV;
 368
 369                 pkt_setup_dev(MKDEV(major, minor), NULL);
 370
 371                 module_put(THIS_MODULE);
 372
 373                 return count;
 374         }
 375
 376         return -EINVAL;
 377 }
 378
 379 static ssize_t class_pktcdvd_store_remove(struct class *c, const char *buf,
 380                                         size_t count)
 381 {
 382         unsigned int major, minor;
 383         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 384                 pkt_remove_dev(MKDEV(major, minor));
 385                 return count;
 386         }
 387         return -EINVAL;
 388 }
 389
 390 static struct class_attribute class_pktcdvd_attrs[] = {
 391  __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
 392  __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
 393  __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
 394  __ATTR_NULL
 395 };
 396
 397
 398 static int pkt_sysfs_init(void)
 399 {
 400         int ret = 0;
 401
 402         /*
 403          * create control files in sysfs
 404          * /sys/class/pktcdvd/...
 405          */
 406         class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
 407         if (!class_pktcdvd)
 408                 return -ENOMEM;
 409         class_pktcdvd->name = DRIVER_NAME;
 410         class_pktcdvd->owner = THIS_MODULE;
 411         class_pktcdvd->class_release = class_pktcdvd_release;
 412         class_pktcdvd->class_attrs = class_pktcdvd_attrs;
 413         ret = class_register(class_pktcdvd);
 414         if (ret) {
 415                 kfree(class_pktcdvd);
 416                 class_pktcdvd = NULL;
 417                 printk(DRIVER_NAME": failed to create class pktcdvd\n");
 418                 return ret;
 419         }
 420         return 0;
 421 }
 422
 423 static void pkt_sysfs_cleanup(void)
 424 {
 425         if (class_pktcdvd)
 426                 class_destroy(class_pktcdvd);
 427         class_pktcdvd = NULL;
 428 }
 429
 430 /********************************************************************
 431   entries in debugfs
 432
 433   /sys/kernel/debug/pktcdvd[0-7]/
 434                         info
 435
 436  *******************************************************************/
 437
 438 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
 439 {
 440         return pkt_seq_show(m, p);
 441 }
 442
 443 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
 444 {
 445         return single_open(file, pkt_debugfs_seq_show, inode->i_private);
 446 }
 447
 448 static const struct file_operations debug_fops = {
 449         .open           = pkt_debugfs_fops_open,
 450         .read           = seq_read,
 451         .llseek         = seq_lseek,
 452         .release        = single_release,
 453         .owner          = THIS_MODULE,
 454 };
 455
 456 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 457 {
 458         if (!pkt_debugfs_root)
 459                 return;
 460         pd->dfs_f_info = NULL;
 461         pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
 462         if (IS_ERR(pd->dfs_d_root)) {
 463                 pd->dfs_d_root = NULL;
 464                 return;
 465         }
 466         pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
 467                                 pd->dfs_d_root, pd, &debug_fops);
 468         if (IS_ERR(pd->dfs_f_info)) {
 469                 pd->dfs_f_info = NULL;
 470                 return;
 471         }
 472 }
 473
 474 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
 475 {
 476         if (!pkt_debugfs_root)
 477                 return;
 478         if (pd->dfs_f_info)
 479                 debugfs_remove(pd->dfs_f_info);
 480         pd->dfs_f_info = NULL;
 481         if (pd->dfs_d_root)
 482                 debugfs_remove(pd->dfs_d_root);
 483         pd->dfs_d_root = NULL;
 484 }
 485
 486 static void pkt_debugfs_init(void)
 487 {
 488         pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
 489         if (IS_ERR(pkt_debugfs_root)) {
 490                 pkt_debugfs_root = NULL;
 491                 return;
 492         }
 493 }
 494
 495 static void pkt_debugfs_cleanup(void)
 496 {
 497         if (!pkt_debugfs_root)
 498                 return;
 499         debugfs_remove(pkt_debugfs_root);
 500         pkt_debugfs_root = NULL;
 501 }
 502
 503 /* ----------------------------------------------------------*/
 504
 505
 506 static void pkt_bio_finished(struct pktcdvd_device *pd)
 507 {
 508         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
 509         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
 510                 VPRINTK(DRIVER_NAME": queue empty\n");
 511                 atomic_set(&pd->iosched.attention, 1);
 512                 wake_up(&pd->wqueue);
 513         }
 514 }
 515
 516 static void pkt_bio_destructor(struct bio *bio)
 517 {
 518         kfree(bio->bi_io_vec);
 519         kfree(bio);
 520 }
 521
 522 static struct bio *pkt_bio_alloc(int nr_iovecs)
 523 {
 524         struct bio_vec *bvl = NULL;
 525         struct bio *bio;
 526
 527         bio = kmalloc(sizeof(struct bio), GFP_KERNEL);
 528         if (!bio)
 529                 goto no_bio;
 530         bio_init(bio);
 531
 532         bvl = kcalloc(nr_iovecs, sizeof(struct bio_vec), GFP_KERNEL);
 533         if (!bvl)
 534                 goto no_bvl;
 535
 536         bio->bi_max_vecs = nr_iovecs;
 537         bio->bi_io_vec = bvl;
 538         bio->bi_destructor = pkt_bio_destructor;
 539
 540         return bio;
 541
 542  no_bvl:
 543         kfree(bio);
 544  no_bio:
 545         return NULL;
 546 }
 547
 548 /*
 549  * Allocate a packet_data struct
 550  */
 551 static struct packet_data *pkt_alloc_packet_data(int frames)
 552 {
 553         int i;
 554         struct packet_data *pkt;
 555
 556         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 557         if (!pkt)
 558                 goto no_pkt;
 559
 560         pkt->frames = frames;
 561         pkt->w_bio = pkt_bio_alloc(frames);
 562         if (!pkt->w_bio)
 563                 goto no_bio;
 564
 565         for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 566                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 567                 if (!pkt->pages[i])
 568                         goto no_page;
 569         }
 570
 571         spin_lock_init(&pkt->lock);
 572         bio_list_init(&pkt->orig_bios);
 573
 574         for (i = 0; i < frames; i++) {
 575                 struct bio *bio = pkt_bio_alloc(1);
 576                 if (!bio)
 577                         goto no_rd_bio;
 578                 pkt->r_bios[i] = bio;
 579         }
 580
 581         return pkt;
 582
 583 no_rd_bio:
 584         for (i = 0; i < frames; i++) {
 585                 struct bio *bio = pkt->r_bios[i];
 586                 if (bio)
 587                         bio_put(bio);
 588         }
 589
 590 no_page:
 591         for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 592                 if (pkt->pages[i])
 593                         __free_page(pkt->pages[i]);
 594         bio_put(pkt->w_bio);
 595 no_bio:
 596         kfree(pkt);
 597 no_pkt:
 598         return NULL;
 599 }
 600
 601 /*
 602  * Free a packet_data struct
 603  */
 604 static void pkt_free_packet_data(struct packet_data *pkt)
 605 {
 606         int i;
 607
 608         for (i = 0; i < pkt->frames; i++) {
 609                 struct bio *bio = pkt->r_bios[i];
 610                 if (bio)
 611                         bio_put(bio);
 612         }
 613         for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 614                 __free_page(pkt->pages[i]);
 615         bio_put(pkt->w_bio);
 616         kfree(pkt);
 617 }
 618
 619 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 620 {
 621         struct packet_data *pkt, *next;
 622
 623         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 624
 625         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 626                 pkt_free_packet_data(pkt);
 627         }
 628         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 629 }
 630
 631 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 632 {
 633         struct packet_data *pkt;
 634
 635         BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
 636
 637         while (nr_packets > 0) {
 638                 pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 639                 if (!pkt) {
 640                         pkt_shrink_pktlist(pd);
 641                         return 0;
 642                 }
 643                 pkt->id = nr_packets;
 644                 pkt->pd = pd;
 645                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 646                 nr_packets--;
 647         }
 648         return 1;
 649 }
 650
 651 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 652 {
 653         struct rb_node *n = rb_next(&node->rb_node);
 654         if (!n)
 655                 return NULL;
 656         return rb_entry(n, struct pkt_rb_node, rb_node);
 657 }
 658
 659 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 660 {
 661         rb_erase(&node->rb_node, &pd->bio_queue);
 662         mempool_free(node, pd->rb_pool);
 663         pd->bio_queue_size--;
 664         BUG_ON(pd->bio_queue_size < 0);
 665 }
 666
 667 /*
 668  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 669  */
 670 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 671 {
 672         struct rb_node *n = pd->bio_queue.rb_node;
 673         struct rb_node *next;
 674         struct pkt_rb_node *tmp;
 675
 676         if (!n) {
 677                 BUG_ON(pd->bio_queue_size > 0);
 678                 return NULL;
 679         }
 680
 681         for (;;) {
 682                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 683                 if (s <= tmp->bio->bi_sector)
 684                         next = n->rb_left;
 685                 else
 686                         next = n->rb_right;
 687                 if (!next)
 688                         break;
 689                 n = next;
 690         }
 691
 692         if (s > tmp->bio->bi_sector) {
 693                 tmp = pkt_rbtree_next(tmp);
 694                 if (!tmp)
 695                         return NULL;
 696         }
 697         BUG_ON(s > tmp->bio->bi_sector);
 698         return tmp;
 699 }
 700
 701 /*
 702  * Insert a node into the pd->bio_queue rb tree.
 703  */
 704 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 705 {
 706         struct rb_node **p = &pd->bio_queue.rb_node;
 707         struct rb_node *parent = NULL;
 708         sector_t s = node->bio->bi_sector;
 709         struct pkt_rb_node *tmp;
 710
 711         while (*p) {
 712                 parent = *p;
 713                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 714                 if (s < tmp->bio->bi_sector)
 715                         p = &(*p)->rb_left;
 716                 else
 717                         p = &(*p)->rb_right;
 718         }
 719         rb_link_node(&node->rb_node, parent, p);
 720         rb_insert_color(&node->rb_node, &pd->bio_queue);
 721         pd->bio_queue_size++;
 722 }
 723
 724 /*
 725  * Send a packet_command to the underlying block device and
 726  * wait for completion.
 727  */
 728 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 729 {
 730         struct request_queue *q = bdev_get_queue(pd->bdev);
 731         struct request *rq;
 732         int ret = 0;
 733
 734         rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 735                              WRITE : READ, __GFP_WAIT);
 736
 737         if (cgc->buflen) {
 738                 if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
 739                         goto out;
 740         }
 741
 742         rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 743         memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 744
 745         rq->timeout = 60*HZ;
 746         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 747         rq->cmd_flags |= REQ_HARDBARRIER;
 748         if (cgc->quiet)
 749                 rq->cmd_flags |= REQ_QUIET;
 750
 751         blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
 752         if (rq->errors)
 753                 ret = -EIO;
 754 out:
 755         blk_put_request(rq);
 756         return ret;
 757 }
 758
 759 /*
 760  * A generic sense dump / resolve mechanism should be implemented across
 761  * all ATAPI + SCSI devices.
 762  */
 763 static void pkt_dump_sense(struct packet_command *cgc)
 764 {
 765         static char *info[9] = { "No sense", "Recovered error", "Not ready",
 766                                  "Medium error", "Hardware error", "Illegal request",
 767                                  "Unit attention", "Data protect", "Blank check" };
 768         int i;
 769         struct request_sense *sense = cgc->sense;
 770
 771         printk(DRIVER_NAME":");
 772         for (i = 0; i < CDROM_PACKET_SIZE; i++)
 773                 printk(" %02x", cgc->cmd[i]);
 774         printk(" - ");
 775
 776         if (sense == NULL) {
 777                 printk("no sense\n");
 778                 return;
 779         }
 780
 781         printk("sense %02x.%02x.%02x", sense->sense_key, sense->asc, sense->ascq);
 782
 783         if (sense->sense_key > 8) {
 784                 printk(" (INVALID)\n");
 785                 return;
 786         }
 787
 788         printk(" (%s)\n", info[sense->sense_key]);
 789 }
 790
 791 /*
 792  * flush the drive cache to media
 793  */
 794 static int pkt_flush_cache(struct pktcdvd_device *pd)
 795 {
 796         struct packet_command cgc;
 797
 798         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 799         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 800         cgc.quiet = 1;
 801
 802         /*
 803          * the IMMED bit -- we default to not setting it, although that
 804          * would allow a much faster close, this is safer
 805          */
 806 #if 0
 807         cgc.cmd[1] = 1 << 1;
 808 #endif
 809         return pkt_generic_packet(pd, &cgc);
 810 }
 811
 812 /*
 813  * speed is given as the normal factor, e.g. 4 for 4x
 814  */
 815 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 816                                 unsigned write_speed, unsigned read_speed)
 817 {
 818         struct packet_command cgc;
 819         struct request_sense sense;
 820         int ret;
 821
 822         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 823         cgc.sense = &sense;
 824         cgc.cmd[0] = GPCMD_SET_SPEED;
 825         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 826         cgc.cmd[3] = read_speed & 0xff;
 827         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 828         cgc.cmd[5] = write_speed & 0xff;
 829
 830         if ((ret = pkt_generic_packet(pd, &cgc)))
 831                 pkt_dump_sense(&cgc);
 832
 833         return ret;
 834 }
 835
 836 /*
 837  * Queue a bio for processing by the low-level CD device. Must be called
 838  * from process context.
 839  */
 840 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 841 {
 842         spin_lock(&pd->iosched.lock);
 843         if (bio_data_dir(bio) == READ)
 844                 bio_list_add(&pd->iosched.read_queue, bio);
 845         else
 846                 bio_list_add(&pd->iosched.write_queue, bio);
 847         spin_unlock(&pd->iosched.lock);
 848
 849         atomic_set(&pd->iosched.attention, 1);
 850         wake_up(&pd->wqueue);
 851 }
 852
 853 /*
 854  * Process the queued read/write requests. This function handles special
 855  * requirements for CDRW drives:
 856  * - A cache flush command must be inserted before a read request if the
 857  *   previous request was a write.
 858  * - Switching between reading and writing is slow, so don't do it more often
 859  *   than necessary.
 860  * - Optimize for throughput at the expense of latency. This means that streaming
 861  *   writes will never be interrupted by a read, but if the drive has to seek
 862  *   before the next write, switch to reading instead if there are any pending
 863  *   read requests.
 864  * - Set the read speed according to current usage pattern. When only reading
 865  *   from the device, it's best to use the highest possible read speed, but
 866  *   when switching often between reading and writing, it's better to have the
 867  *   same read and write speeds.
 868  */
 869 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 870 {
 871
 872         if (atomic_read(&pd->iosched.attention) == 0)
 873                 return;
 874         atomic_set(&pd->iosched.attention, 0);
 875
 876         for (;;) {
 877                 struct bio *bio;
 878                 int reads_queued, writes_queued;
 879
 880                 spin_lock(&pd->iosched.lock);
 881                 reads_queued = !bio_list_empty(&pd->iosched.read_queue);
 882                 writes_queued = !bio_list_empty(&pd->iosched.write_queue);
 883                 spin_unlock(&pd->iosched.lock);
 884
 885                 if (!reads_queued && !writes_queued)
 886                         break;
 887
 888                 if (pd->iosched.writing) {
 889                         int need_write_seek = 1;
 890                         spin_lock(&pd->iosched.lock);
 891                         bio = bio_list_peek(&pd->iosched.write_queue);
 892                         spin_unlock(&pd->iosched.lock);
 893                         if (bio && (bio->bi_sector == pd->iosched.last_write))
 894                                 need_write_seek = 0;
 895                         if (need_write_seek && reads_queued) {
 896                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 897                                         VPRINTK(DRIVER_NAME": write, waiting\n");
 898                                         break;
 899                                 }
 900                                 pkt_flush_cache(pd);
 901                                 pd->iosched.writing = 0;
 902                         }
 903                 } else {
 904                         if (!reads_queued && writes_queued) {
 905                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 906                                         VPRINTK(DRIVER_NAME": read, waiting\n");
 907                                         break;
 908                                 }
 909                                 pd->iosched.writing = 1;
 910                         }
 911                 }
 912
 913                 spin_lock(&pd->iosched.lock);
 914                 if (pd->iosched.writing)
 915                         bio = bio_list_pop(&pd->iosched.write_queue);
 916                 else
 917                         bio = bio_list_pop(&pd->iosched.read_queue);
 918                 spin_unlock(&pd->iosched.lock);
 919
 920                 if (!bio)
 921                         continue;
 922
 923                 if (bio_data_dir(bio) == READ)
 924                         pd->iosched.successive_reads += bio->bi_size >> 10;
 925                 else {
 926                         pd->iosched.successive_reads = 0;
 927                         pd->iosched.last_write = bio->bi_sector + bio_sectors(bio);
 928                 }
 929                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 930                         if (pd->read_speed == pd->write_speed) {
 931                                 pd->read_speed = MAX_SPEED;
 932                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 933                         }
 934                 } else {
 935                         if (pd->read_speed != pd->write_speed) {
 936                                 pd->read_speed = pd->write_speed;
 937                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 938                         }
 939                 }
 940
 941                 atomic_inc(&pd->cdrw.pending_bios);
 942                 generic_make_request(bio);
 943         }
 944 }
 945
 946 /*
 947  * Special care is needed if the underlying block device has a small
 948  * max_phys_segments value.
 949  */
 950 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 951 {
 952         if ((pd->settings.size << 9) / CD_FRAMESIZE
 953             <= queue_max_segments(q)) {
 954                 /*
 955                  * The cdrom device can handle one segment/frame
 956                  */
 957                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 958                 return 0;
 959         } else if ((pd->settings.size << 9) / PAGE_SIZE
 960                    <= queue_max_segments(q)) {
 961                 /*
 962                  * We can handle this case at the expense of some extra memory
 963                  * copies during write operations
 964                  */
 965                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 966                 return 0;
 967         } else {
 968                 printk(DRIVER_NAME": cdrom max_phys_segments too small\n");
 969                 return -EIO;
 970         }
 971 }
 972
 973 /*
 974  * Copy CD_FRAMESIZE bytes from src_bio into a destination page
 975  */
 976 static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
 977 {
 978         unsigned int copy_size = CD_FRAMESIZE;
 979
 980         while (copy_size > 0) {
 981                 struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
 982                 void *vfrom = kmap_atomic(src_bvl->bv_page, KM_USER0) +
 983                         src_bvl->bv_offset + offs;
 984                 void *vto = page_address(dst_page) + dst_offs;
 985                 int len = min_t(int, copy_size, src_bvl->bv_len - offs);
 986
 987                 BUG_ON(len < 0);
 988                 memcpy(vto, vfrom, len);
 989                 kunmap_atomic(vfrom, KM_USER0);
 990
 991                 seg++;
 992                 offs = 0;
 993                 dst_offs += len;
 994                 copy_size -= len;
 995         }
 996 }
 997
 998 /*
 999  * Copy all data for this packet to pkt->pages[], so that
1000  * a) The number of required segments for the write bio is minimized, which
1001  *    is necessary for some scsi controllers.
1002  * b) The data can be used as cache to avoid read requests if we receive a
1003  *    new write request for the same zone.
1004  */
1005 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
1006 {
1007         int f, p, offs;
1008
1009         /* Copy all data to pkt->pages[] */
1010         p = 0;
1011         offs = 0;
1012         for (f = 0; f < pkt->frames; f++) {
1013                 if (bvec[f].bv_page != pkt->pages[p]) {
1014                         void *vfrom = kmap_atomic(bvec[f].bv_page, KM_USER0) + bvec[f].bv_offset;
1015                         void *vto = page_address(pkt->pages[p]) + offs;
1016                         memcpy(vto, vfrom, CD_FRAMESIZE);
1017                         kunmap_atomic(vfrom, KM_USER0);
1018                         bvec[f].bv_page = pkt->pages[p];
1019                         bvec[f].bv_offset = offs;
1020                 } else {
1021                         BUG_ON(bvec[f].bv_offset != offs);
1022                 }
1023                 offs += CD_FRAMESIZE;
1024                 if (offs >= PAGE_SIZE) {
1025                         offs = 0;
1026                         p++;
1027                 }
1028         }
1029 }
1030
1031 static void pkt_end_io_read(struct bio *bio, int err)
1032 {
1033         struct packet_data *pkt = bio->bi_private;
1034         struct pktcdvd_device *pd = pkt->pd;
1035         BUG_ON(!pd);
1036
1037         VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
1038                 (unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
1039
1040         if (err)
1041                 atomic_inc(&pkt->io_errors);
1042         if (atomic_dec_and_test(&pkt->io_wait)) {
1043                 atomic_inc(&pkt->run_sm);
1044                 wake_up(&pd->wqueue);
1045         }
1046         pkt_bio_finished(pd);
1047 }
1048
1049 static void pkt_end_io_packet_write(struct bio *bio, int err)
1050 {
1051         struct packet_data *pkt = bio->bi_private;
1052         struct pktcdvd_device *pd = pkt->pd;
1053         BUG_ON(!pd);
1054
1055         VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
1056
1057         pd->stats.pkt_ended++;
1058
1059         pkt_bio_finished(pd);
1060         atomic_dec(&pkt->io_wait);
1061         atomic_inc(&pkt->run_sm);
1062         wake_up(&pd->wqueue);
1063 }
1064
1065 /*
1066  * Schedule reads for the holes in a packet
1067  */
1068 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1069 {
1070         int frames_read = 0;
1071         struct bio *bio;
1072         int f;
1073         char written[PACKET_MAX_SIZE];
1074
1075         BUG_ON(bio_list_empty(&pkt->orig_bios));
1076
1077         atomic_set(&pkt->io_wait, 0);
1078         atomic_set(&pkt->io_errors, 0);
1079
1080         /*
1081          * Figure out which frames we need to read before we can write.
1082          */
1083         memset(written, 0, sizeof(written));
1084         spin_lock(&pkt->lock);
1085         bio_list_for_each(bio, &pkt->orig_bios) {
1086                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1087                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1088                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1089                 BUG_ON(first_frame < 0);
1090                 BUG_ON(first_frame + num_frames > pkt->frames);
1091                 for (f = first_frame; f < first_frame + num_frames; f++)
1092                         written[f] = 1;
1093         }
1094         spin_unlock(&pkt->lock);
1095
1096         if (pkt->cache_valid) {
1097                 VPRINTK("pkt_gather_data: zone %llx cached\n",
1098                         (unsigned long long)pkt->sector);
1099                 goto out_account;
1100         }
1101
1102         /*
1103          * Schedule reads for missing parts of the packet.
1104          */
1105         for (f = 0; f < pkt->frames; f++) {
1106                 struct bio_vec *vec;
1107
1108                 int p, offset;
1109                 if (written[f])
1110                         continue;
1111                 bio = pkt->r_bios[f];
1112                 vec = bio->bi_io_vec;
1113                 bio_init(bio);
1114                 bio->bi_max_vecs = 1;
1115                 bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1116                 bio->bi_bdev = pd->bdev;
1117                 bio->bi_end_io = pkt_end_io_read;
1118                 bio->bi_private = pkt;
1119                 bio->bi_io_vec = vec;
1120                 bio->bi_destructor = pkt_bio_destructor;
1121
1122                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1123                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1124                 VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
1125                         f, pkt->pages[p], offset);
1126                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1127                         BUG();
1128
1129                 atomic_inc(&pkt->io_wait);
1130                 bio->bi_rw = READ;
1131                 pkt_queue_bio(pd, bio);
1132                 frames_read++;
1133         }
1134
1135 out_account:
1136         VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
1137                 frames_read, (unsigned long long)pkt->sector);
1138         pd->stats.pkt_started++;
1139         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1140 }
1141
1142 /*
1143  * Find a packet matching zone, or the least recently used packet if
1144  * there is no match.
1145  */
1146 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1147 {
1148         struct packet_data *pkt;
1149
1150         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1151                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1152                         list_del_init(&pkt->list);
1153                         if (pkt->sector != zone)
1154                                 pkt->cache_valid = 0;
1155                         return pkt;
1156                 }
1157         }
1158         BUG();
1159         return NULL;
1160 }
1161
1162 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1163 {
1164         if (pkt->cache_valid) {
1165                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1166         } else {
1167                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1168         }
1169 }
1170
1171 /*
1172  * recover a failed write, query for relocation if possible
1173  *
1174  * returns 1 if recovery is possible, or 0 if not
1175  *
1176  */
1177 static int pkt_start_recovery(struct packet_data *pkt)
1178 {
1179         /*
1180          * FIXME. We need help from the file system to implement
1181          * recovery handling.
1182          */
1183         return 0;
1184 #if 0
1185         struct request *rq = pkt->rq;
1186         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1187         struct block_device *pkt_bdev;
1188         struct super_block *sb = NULL;
1189         unsigned long old_block, new_block;
1190         sector_t new_sector;
1191
1192         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1193         if (pkt_bdev) {
1194                 sb = get_super(pkt_bdev);
1195                 bdput(pkt_bdev);
1196         }
1197
1198         if (!sb)
1199                 return 0;
1200
1201         if (!sb->s_op || !sb->s_op->relocate_blocks)
1202                 goto out;
1203
1204         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1205         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1206                 goto out;
1207
1208         new_sector = new_block * (CD_FRAMESIZE >> 9);
1209         pkt->sector = new_sector;
1210
1211         pkt->bio->bi_sector = new_sector;
1212         pkt->bio->bi_next = NULL;
1213         pkt->bio->bi_flags = 1 << BIO_UPTODATE;
1214         pkt->bio->bi_idx = 0;
1215
1216         BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
1217         BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
1218         BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
1219         BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
1220         BUG_ON(pkt->bio->bi_private != pkt);
1221
1222         drop_super(sb);
1223         return 1;
1224
1225 out:
1226         drop_super(sb);
1227         return 0;
1228 #endif
1229 }
1230
1231 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1232 {
1233 #if PACKET_DEBUG > 1
1234         static const char *state_name[] = {
1235                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1236         };
1237         enum packet_data_state old_state = pkt->state;
1238         VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
1239                 state_name[old_state], state_name[state]);
1240 #endif
1241         pkt->state = state;
1242 }
1243
1244 /*
1245  * Scan the work queue to see if we can start a new packet.
1246  * returns non-zero if any work was done.
1247  */
1248 static int pkt_handle_queue(struct pktcdvd_device *pd)
1249 {
1250         struct packet_data *pkt, *p;
1251         struct bio *bio = NULL;
1252         sector_t zone = 0; /* Suppress gcc warning */
1253         struct pkt_rb_node *node, *first_node;
1254         struct rb_node *n;
1255         int wakeup;
1256
1257         VPRINTK("handle_queue\n");
1258
1259         atomic_set(&pd->scan_queue, 0);
1260
1261         if (list_empty(&pd->cdrw.pkt_free_list)) {
1262                 VPRINTK("handle_queue: no pkt\n");
1263                 return 0;
1264         }
1265
1266         /*
1267          * Try to find a zone we are not already working on.
1268          */
1269         spin_lock(&pd->lock);
1270         first_node = pkt_rbtree_find(pd, pd->current_sector);
1271         if (!first_node) {
1272                 n = rb_first(&pd->bio_queue);
1273                 if (n)
1274                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1275         }
1276         node = first_node;
1277         while (node) {
1278                 bio = node->bio;
1279                 zone = ZONE(bio->bi_sector, pd);
1280                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1281                         if (p->sector == zone) {
1282                                 bio = NULL;
1283                                 goto try_next_bio;
1284                         }
1285                 }
1286                 break;
1287 try_next_bio:
1288                 node = pkt_rbtree_next(node);
1289                 if (!node) {
1290                         n = rb_first(&pd->bio_queue);
1291                         if (n)
1292                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1293                 }
1294                 if (node == first_node)
1295                         node = NULL;
1296         }
1297         spin_unlock(&pd->lock);
1298         if (!bio) {
1299                 VPRINTK("handle_queue: no bio\n");
1300                 return 0;
1301         }
1302
1303         pkt = pkt_get_packet_data(pd, zone);
1304
1305         pd->current_sector = zone + pd->settings.size;
1306         pkt->sector = zone;
1307         BUG_ON(pkt->frames != pd->settings.size >> 2);
1308         pkt->write_size = 0;
1309
1310         /*
1311          * Scan work queue for bios in the same zone and link them
1312          * to this packet.
1313          */
1314         spin_lock(&pd->lock);
1315         VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
1316         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1317                 bio = node->bio;
1318                 VPRINTK("pkt_handle_queue: found zone=%llx\n",
1319                         (unsigned long long)ZONE(bio->bi_sector, pd));
1320                 if (ZONE(bio->bi_sector, pd) != zone)
1321                         break;
1322                 pkt_rbtree_erase(pd, node);
1323                 spin_lock(&pkt->lock);
1324                 bio_list_add(&pkt->orig_bios, bio);
1325                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
1326                 spin_unlock(&pkt->lock);
1327         }
1328         /* check write congestion marks, and if bio_queue_size is
1329            below, wake up any waiters */
1330         wakeup = (pd->write_congestion_on > 0
1331                         && pd->bio_queue_size <= pd->write_congestion_off);
1332         spin_unlock(&pd->lock);
1333         if (wakeup) {
1334                 clear_bdi_congested(&pd->disk->queue->backing_dev_info,
1335                                         BLK_RW_ASYNC);
1336         }
1337
1338         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1339         pkt_set_state(pkt, PACKET_WAITING_STATE);
1340         atomic_set(&pkt->run_sm, 1);
1341
1342         spin_lock(&pd->cdrw.active_list_lock);
1343         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1344         spin_unlock(&pd->cdrw.active_list_lock);
1345
1346         return 1;
1347 }
1348
1349 /*
1350  * Assemble a bio to write one packet and queue the bio for processing
1351  * by the underlying block device.
1352  */
1353 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1354 {
1355         struct bio *bio;
1356         int f;
1357         int frames_write;
1358         struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1359
1360         for (f = 0; f < pkt->frames; f++) {
1361                 bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1362                 bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1363         }
1364
1365         /*
1366          * Fill-in bvec with data from orig_bios.
1367          */
1368         frames_write = 0;
1369         spin_lock(&pkt->lock);
1370         bio_list_for_each(bio, &pkt->orig_bios) {
1371                 int segment = bio->bi_idx;
1372                 int src_offs = 0;
1373                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1374                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1375                 BUG_ON(first_frame < 0);
1376                 BUG_ON(first_frame + num_frames > pkt->frames);
1377                 for (f = first_frame; f < first_frame + num_frames; f++) {
1378                         struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
1379
1380                         while (src_offs >= src_bvl->bv_len) {
1381                                 src_offs -= src_bvl->bv_len;
1382                                 segment++;
1383                                 BUG_ON(segment >= bio->bi_vcnt);
1384                                 src_bvl = bio_iovec_idx(bio, segment);
1385                         }
1386
1387                         if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
1388                                 bvec[f].bv_page = src_bvl->bv_page;
1389                                 bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
1390                         } else {
1391                                 pkt_copy_bio_data(bio, segment, src_offs,
1392                                                   bvec[f].bv_page, bvec[f].bv_offset);
1393                         }
1394                         src_offs += CD_FRAMESIZE;
1395                         frames_write++;
1396                 }
1397         }
1398         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1399         spin_unlock(&pkt->lock);
1400
1401         VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
1402                 frames_write, (unsigned long long)pkt->sector);
1403         BUG_ON(frames_write != pkt->write_size);
1404
1405         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1406                 pkt_make_local_copy(pkt, bvec);
1407                 pkt->cache_valid = 1;
1408         } else {
1409                 pkt->cache_valid = 0;
1410         }
1411
1412         /* Start the write request */
1413         bio_init(pkt->w_bio);
1414         pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
1415         pkt->w_bio->bi_sector = pkt->sector;
1416         pkt->w_bio->bi_bdev = pd->bdev;
1417         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1418         pkt->w_bio->bi_private = pkt;
1419         pkt->w_bio->bi_io_vec = bvec;
1420         pkt->w_bio->bi_destructor = pkt_bio_destructor;
1421         for (f = 0; f < pkt->frames; f++)
1422                 if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1423                         BUG();
1424         VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
1425
1426         atomic_set(&pkt->io_wait, 1);
1427         pkt->w_bio->bi_rw = WRITE;
1428         pkt_queue_bio(pd, pkt->w_bio);
1429 }
1430
1431 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1432 {
1433         struct bio *bio;
1434
1435         if (!uptodate)
1436                 pkt->cache_valid = 0;
1437
1438         /* Finish all bios corresponding to this packet */
1439         while ((bio = bio_list_pop(&pkt->orig_bios)))
1440                 bio_endio(bio, uptodate ? 0 : -EIO);
1441 }
1442
1443 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1444 {
1445         int uptodate;
1446
1447         VPRINTK("run_state_machine: pkt %d\n", pkt->id);
1448
1449         for (;;) {
1450                 switch (pkt->state) {
1451                 case PACKET_WAITING_STATE:
1452                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1453                                 return;
1454
1455                         pkt->sleep_time = 0;
1456                         pkt_gather_data(pd, pkt);
1457                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1458                         break;
1459
1460                 case PACKET_READ_WAIT_STATE:
1461                         if (atomic_read(&pkt->io_wait) > 0)
1462                                 return;
1463
1464                         if (atomic_read(&pkt->io_errors) > 0) {
1465                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1466                         } else {
1467                                 pkt_start_write(pd, pkt);
1468                         }
1469                         break;
1470
1471                 case PACKET_WRITE_WAIT_STATE:
1472                         if (atomic_read(&pkt->io_wait) > 0)
1473                                 return;
1474
1475                         if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1476                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1477                         } else {
1478                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1479                         }
1480                         break;
1481
1482                 case PACKET_RECOVERY_STATE:
1483                         if (pkt_start_recovery(pkt)) {
1484                                 pkt_start_write(pd, pkt);
1485                         } else {
1486                                 VPRINTK("No recovery possible\n");
1487                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1488                         }
1489                         break;
1490
1491                 case PACKET_FINISHED_STATE:
1492                         uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1493                         pkt_finish_packet(pkt, uptodate);
1494                         return;
1495
1496                 default:
1497                         BUG();
1498                         break;
1499                 }
1500         }
1501 }
1502
1503 static void pkt_handle_packets(struct pktcdvd_device *pd)
1504 {
1505         struct packet_data *pkt, *next;
1506
1507         VPRINTK("pkt_handle_packets\n");
1508
1509         /*
1510          * Run state machine for active packets
1511          */
1512         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1513                 if (atomic_read(&pkt->run_sm) > 0) {
1514                         atomic_set(&pkt->run_sm, 0);
1515                         pkt_run_state_machine(pd, pkt);
1516                 }
1517         }
1518
1519         /*
1520          * Move no longer active packets to the free list
1521          */
1522         spin_lock(&pd->cdrw.active_list_lock);
1523         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1524                 if (pkt->state == PACKET_FINISHED_STATE) {
1525                         list_del(&pkt->list);
1526                         pkt_put_packet_data(pd, pkt);
1527                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1528                         atomic_set(&pd->scan_queue, 1);
1529                 }
1530         }
1531         spin_unlock(&pd->cdrw.active_list_lock);
1532 }
1533
1534 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1535 {
1536         struct packet_data *pkt;
1537         int i;
1538
1539         for (i = 0; i < PACKET_NUM_STATES; i++)
1540                 states[i] = 0;
1541
1542         spin_lock(&pd->cdrw.active_list_lock);
1543         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1544                 states[pkt->state]++;
1545         }
1546         spin_unlock(&pd->cdrw.active_list_lock);
1547 }
1548
1549 /*
1550  * kcdrwd is woken up when writes have been queued for one of our
1551  * registered devices
1552  */
1553 static int kcdrwd(void *foobar)
1554 {
1555         struct pktcdvd_device *pd = foobar;
1556         struct packet_data *pkt;
1557         long min_sleep_time, residue;
1558
1559         set_user_nice(current, -20);
1560         set_freezable();
1561
1562         for (;;) {
1563                 DECLARE_WAITQUEUE(wait, current);
1564
1565                 /*
1566                  * Wait until there is something to do
1567                  */
1568                 add_wait_queue(&pd->wqueue, &wait);
1569                 for (;;) {
1570                         set_current_state(TASK_INTERRUPTIBLE);
1571
1572                         /* Check if we need to run pkt_handle_queue */
1573                         if (atomic_read(&pd->scan_queue) > 0)
1574                                 goto work_to_do;
1575
1576                         /* Check if we need to run the state machine for some packet */
1577                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1578                                 if (atomic_read(&pkt->run_sm) > 0)
1579                                         goto work_to_do;
1580                         }
1581
1582                         /* Check if we need to process the iosched queues */
1583                         if (atomic_read(&pd->iosched.attention) != 0)
1584                                 goto work_to_do;
1585
1586                         /* Otherwise, go to sleep */
1587                         if (PACKET_DEBUG > 1) {
1588                                 int states[PACKET_NUM_STATES];
1589                                 pkt_count_states(pd, states);
1590                                 VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1591                                         states[0], states[1], states[2], states[3],
1592                                         states[4], states[5]);
1593                         }
1594
1595                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1596                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1597                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1598                                         min_sleep_time = pkt->sleep_time;
1599                         }
1600
1601                         generic_unplug_device(bdev_get_queue(pd->bdev));
1602
1603                         VPRINTK("kcdrwd: sleeping\n");
1604                         residue = schedule_timeout(min_sleep_time);
1605                         VPRINTK("kcdrwd: wake up\n");
1606
1607                         /* make swsusp happy with our thread */
1608                         try_to_freeze();
1609
1610                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1611                                 if (!pkt->sleep_time)
1612                                         continue;
1613                                 pkt->sleep_time -= min_sleep_time - residue;
1614                                 if (pkt->sleep_time <= 0) {
1615                                         pkt->sleep_time = 0;
1616                                         atomic_inc(&pkt->run_sm);
1617                                 }
1618                         }
1619
1620                         if (kthread_should_stop())
1621                                 break;
1622                 }
1623 work_to_do:
1624                 set_current_state(TASK_RUNNING);
1625                 remove_wait_queue(&pd->wqueue, &wait);
1626
1627                 if (kthread_should_stop())
1628                         break;
1629
1630                 /*
1631                  * if pkt_handle_queue returns true, we can queue
1632                  * another request.
1633                  */
1634                 while (pkt_handle_queue(pd))
1635                         ;
1636
1637                 /*
1638                  * Handle packet state machine
1639                  */
1640                 pkt_handle_packets(pd);
1641
1642                 /*
1643                  * Handle iosched queues
1644                  */
1645                 pkt_iosched_process_queue(pd);
1646         }
1647
1648         return 0;
1649 }
1650
1651 static void pkt_print_settings(struct pktcdvd_device *pd)
1652 {
1653         printk(DRIVER_NAME": %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
1654         printk("%u blocks, ", pd->settings.size >> 2);
1655         printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
1656 }
1657
1658 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1659 {
1660         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1661
1662         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1663         cgc->cmd[2] = page_code | (page_control << 6);
1664         cgc->cmd[7] = cgc->buflen >> 8;
1665         cgc->cmd[8] = cgc->buflen & 0xff;
1666         cgc->data_direction = CGC_DATA_READ;
1667         return pkt_generic_packet(pd, cgc);
1668 }
1669
1670 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1671 {
1672         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1673         memset(cgc->buffer, 0, 2);
1674         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1675         cgc->cmd[1] = 0x10;             /* PF */
1676         cgc->cmd[7] = cgc->buflen >> 8;
1677         cgc->cmd[8] = cgc->buflen & 0xff;
1678         cgc->data_direction = CGC_DATA_WRITE;
1679         return pkt_generic_packet(pd, cgc);
1680 }
1681
1682 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1683 {
1684         struct packet_command cgc;
1685         int ret;
1686
1687         /* set up command and get the disc info */
1688         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1689         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1690         cgc.cmd[8] = cgc.buflen = 2;
1691         cgc.quiet = 1;
1692
1693         if ((ret = pkt_generic_packet(pd, &cgc)))
1694                 return ret;
1695
1696         /* not all drives have the same disc_info length, so requeue
1697          * packet with the length the drive tells us it can supply
1698          */
1699         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1700                      sizeof(di->disc_information_length);
1701
1702         if (cgc.buflen > sizeof(disc_information))
1703                 cgc.buflen = sizeof(disc_information);
1704
1705         cgc.cmd[8] = cgc.buflen;
1706         return pkt_generic_packet(pd, &cgc);
1707 }
1708
1709 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1710 {
1711         struct packet_command cgc;
1712         int ret;
1713
1714         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1715         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1716         cgc.cmd[1] = type & 3;
1717         cgc.cmd[4] = (track & 0xff00) >> 8;
1718         cgc.cmd[5] = track & 0xff;
1719         cgc.cmd[8] = 8;
1720         cgc.quiet = 1;
1721
1722         if ((ret = pkt_generic_packet(pd, &cgc)))
1723                 return ret;
1724
1725         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1726                      sizeof(ti->track_information_length);
1727
1728         if (cgc.buflen > sizeof(track_information))
1729                 cgc.buflen = sizeof(track_information);
1730
1731         cgc.cmd[8] = cgc.buflen;
1732         return pkt_generic_packet(pd, &cgc);
1733 }
1734
1735 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1736                                                 long *last_written)
1737 {
1738         disc_information di;
1739         track_information ti;
1740         __u32 last_track;
1741         int ret = -1;
1742
1743         if ((ret = pkt_get_disc_info(pd, &di)))
1744                 return ret;
1745
1746         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1747         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1748                 return ret;
1749
1750         /* if this track is blank, try the previous. */
1751         if (ti.blank) {
1752                 last_track--;
1753                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1754                         return ret;
1755         }
1756
1757         /* if last recorded field is valid, return it. */
1758         if (ti.lra_v) {
1759                 *last_written = be32_to_cpu(ti.last_rec_address);
1760         } else {
1761                 /* make it up instead */
1762                 *last_written = be32_to_cpu(ti.track_start) +
1763                                 be32_to_cpu(ti.track_size);
1764                 if (ti.free_blocks)
1765                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1766         }
1767         return 0;
1768 }
1769
1770 /*
1771  * write mode select package based on pd->settings
1772  */
1773 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1774 {
1775         struct packet_command cgc;
1776         struct request_sense sense;
1777         write_param_page *wp;
1778         char buffer[128];
1779         int ret, size;
1780
1781         /* doesn't apply to DVD+RW or DVD-RAM */
1782         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1783                 return 0;
1784
1785         memset(buffer, 0, sizeof(buffer));
1786         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1787         cgc.sense = &sense;
1788         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1789                 pkt_dump_sense(&cgc);
1790                 return ret;
1791         }
1792
1793         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1794         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1795         if (size > sizeof(buffer))
1796                 size = sizeof(buffer);
1797
1798         /*
1799          * now get it all
1800          */
1801         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1802         cgc.sense = &sense;
1803         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1804                 pkt_dump_sense(&cgc);
1805                 return ret;
1806         }
1807
1808         /*
1809          * write page is offset header + block descriptor length
1810          */
1811         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1812
1813         wp->fp = pd->settings.fp;
1814         wp->track_mode = pd->settings.track_mode;
1815         wp->write_type = pd->settings.write_type;
1816         wp->data_block_type = pd->settings.block_mode;
1817
1818         wp->multi_session = 0;
1819
1820 #ifdef PACKET_USE_LS
1821         wp->link_size = 7;
1822         wp->ls_v = 1;
1823 #endif
1824
1825         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1826                 wp->session_format = 0;
1827                 wp->subhdr2 = 0x20;
1828         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1829                 wp->session_format = 0x20;
1830                 wp->subhdr2 = 8;
1831 #if 0
1832                 wp->mcn[0] = 0x80;
1833                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1834 #endif
1835         } else {
1836                 /*
1837                  * paranoia
1838                  */
1839                 printk(DRIVER_NAME": write mode wrong %d\n", wp->data_block_type);
1840                 return 1;
1841         }
1842         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1843
1844         cgc.buflen = cgc.cmd[8] = size;
1845         if ((ret = pkt_mode_select(pd, &cgc))) {
1846                 pkt_dump_sense(&cgc);
1847                 return ret;
1848         }
1849
1850         pkt_print_settings(pd);
1851         return 0;
1852 }
1853
1854 /*
1855  * 1 -- we can write to this track, 0 -- we can't
1856  */
1857 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1858 {
1859         switch (pd->mmc3_profile) {
1860                 case 0x1a: /* DVD+RW */
1861                 case 0x12: /* DVD-RAM */
1862                         /* The track is always writable on DVD+RW/DVD-RAM */
1863                         return 1;
1864                 default:
1865                         break;
1866         }
1867
1868         if (!ti->packet || !ti->fp)
1869                 return 0;
1870
1871         /*
1872          * "good" settings as per Mt Fuji.
1873          */
1874         if (ti->rt == 0 && ti->blank == 0)
1875                 return 1;
1876
1877         if (ti->rt == 0 && ti->blank == 1)
1878                 return 1;
1879
1880         if (ti->rt == 1 && ti->blank == 0)
1881                 return 1;
1882
1883         printk(DRIVER_NAME": bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1884         return 0;
1885 }
1886
1887 /*
1888  * 1 -- we can write to this disc, 0 -- we can't
1889  */
1890 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1891 {
1892         switch (pd->mmc3_profile) {
1893                 case 0x0a: /* CD-RW */
1894                 case 0xffff: /* MMC3 not supported */
1895                         break;
1896                 case 0x1a: /* DVD+RW */
1897                 case 0x13: /* DVD-RW */
1898                 case 0x12: /* DVD-RAM */
1899                         return 1;
1900                 default:
1901                         VPRINTK(DRIVER_NAME": Wrong disc profile (%x)\n", pd->mmc3_profile);
1902                         return 0;
1903         }
1904
1905         /*
1906          * for disc type 0xff we should probably reserve a new track.
1907          * but i'm not sure, should we leave this to user apps? probably.
1908          */
1909         if (di->disc_type == 0xff) {
1910                 printk(DRIVER_NAME": Unknown disc. No track?\n");
1911                 return 0;
1912         }
1913
1914         if (di->disc_type != 0x20 && di->disc_type != 0) {
1915                 printk(DRIVER_NAME": Wrong disc type (%x)\n", di->disc_type);
1916                 return 0;
1917         }
1918
1919         if (di->erasable == 0) {
1920                 printk(DRIVER_NAME": Disc not erasable\n");
1921                 return 0;
1922         }
1923
1924         if (di->border_status == PACKET_SESSION_RESERVED) {
1925                 printk(DRIVER_NAME": Can't write to last track (reserved)\n");
1926                 return 0;
1927         }
1928
1929         return 1;
1930 }
1931
1932 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1933 {
1934         struct packet_command cgc;
1935         unsigned char buf[12];
1936         disc_information di;
1937         track_information ti;
1938         int ret, track;
1939
1940         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1941         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1942         cgc.cmd[8] = 8;
1943         ret = pkt_generic_packet(pd, &cgc);
1944         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1945
1946         memset(&di, 0, sizeof(disc_information));
1947         memset(&ti, 0, sizeof(track_information));
1948
1949         if ((ret = pkt_get_disc_info(pd, &di))) {
1950                 printk("failed get_disc\n");
1951                 return ret;
1952         }
1953
1954         if (!pkt_writable_disc(pd, &di))
1955                 return -EROFS;
1956
1957         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1958
1959         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1960         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1961                 printk(DRIVER_NAME": failed get_track\n");
1962                 return ret;
1963         }
1964
1965         if (!pkt_writable_track(pd, &ti)) {
1966                 printk(DRIVER_NAME": can't write to this track\n");
1967                 return -EROFS;
1968         }
1969
1970         /*
1971          * we keep packet size in 512 byte units, makes it easier to
1972          * deal with request calculations.
1973          */
1974         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1975         if (pd->settings.size == 0) {
1976                 printk(DRIVER_NAME": detected zero packet size!\n");
1977                 return -ENXIO;
1978         }
1979         if (pd->settings.size > PACKET_MAX_SECTORS) {
1980                 printk(DRIVER_NAME": packet size is too big\n");
1981                 return -EROFS;
1982         }
1983         pd->settings.fp = ti.fp;
1984         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1985
1986         if (ti.nwa_v) {
1987                 pd->nwa = be32_to_cpu(ti.next_writable);
1988                 set_bit(PACKET_NWA_VALID, &pd->flags);
1989         }
1990
1991         /*
1992          * in theory we could use lra on -RW media as well and just zero
1993          * blocks that haven't been written yet, but in practice that
1994          * is just a no-go. we'll use that for -R, naturally.
1995          */
1996         if (ti.lra_v) {
1997                 pd->lra = be32_to_cpu(ti.last_rec_address);
1998                 set_bit(PACKET_LRA_VALID, &pd->flags);
1999         } else {
2000                 pd->lra = 0xffffffff;
2001                 set_bit(PACKET_LRA_VALID, &pd->flags);
2002         }
2003
2004         /*
2005          * fine for now
2006          */
2007         pd->settings.link_loss = 7;
2008         pd->settings.write_type = 0;    /* packet */
2009         pd->settings.track_mode = ti.track_mode;
2010
2011         /*
2012          * mode1 or mode2 disc
2013          */
2014         switch (ti.data_mode) {
2015                 case PACKET_MODE1:
2016                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
2017                         break;
2018                 case PACKET_MODE2:
2019                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
2020                         break;
2021                 default:
2022                         printk(DRIVER_NAME": unknown data mode\n");
2023                         return -EROFS;
2024         }
2025         return 0;
2026 }
2027
2028 /*
2029  * enable/disable write caching on drive
2030  */
2031 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
2032                                                 int set)
2033 {
2034         struct packet_command cgc;
2035         struct request_sense sense;
2036         unsigned char buf[64];
2037         int ret;
2038
2039         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
2040         cgc.sense = &sense;
2041         cgc.buflen = pd->mode_offset + 12;
2042
2043         /*
2044          * caching mode page might not be there, so quiet this command
2045          */
2046         cgc.quiet = 1;
2047
2048         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
2049                 return ret;
2050
2051         buf[pd->mode_offset + 10] |= (!!set << 2);
2052
2053         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
2054         ret = pkt_mode_select(pd, &cgc);
2055         if (ret) {
2056                 printk(DRIVER_NAME": write caching control failed\n");
2057                 pkt_dump_sense(&cgc);
2058         } else if (!ret && set)
2059                 printk(DRIVER_NAME": enabled write caching on %s\n", pd->name);
2060         return ret;
2061 }
2062
2063 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
2064 {
2065         struct packet_command cgc;
2066
2067         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2068         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
2069         cgc.cmd[4] = lockflag ? 1 : 0;
2070         return pkt_generic_packet(pd, &cgc);
2071 }
2072
2073 /*
2074  * Returns drive maximum write speed
2075  */
2076 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
2077                                                 unsigned *write_speed)
2078 {
2079         struct packet_command cgc;
2080         struct request_sense sense;
2081         unsigned char buf[256+18];
2082         unsigned char *cap_buf;
2083         int ret, offset;
2084
2085         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
2086         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
2087         cgc.sense = &sense;
2088
2089         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2090         if (ret) {
2091                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2092                              sizeof(struct mode_page_header);
2093                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2094                 if (ret) {
2095                         pkt_dump_sense(&cgc);
2096                         return ret;
2097                 }
2098         }
2099
2100         offset = 20;                        /* Obsoleted field, used by older drives */
2101         if (cap_buf[1] >= 28)
2102                 offset = 28;                /* Current write speed selected */
2103         if (cap_buf[1] >= 30) {
2104                 /* If the drive reports at least one "Logical Unit Write
2105                  * Speed Performance Descriptor Block", use the information
2106                  * in the first block. (contains the highest speed)
2107                  */
2108                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2109                 if (num_spdb > 0)
2110                         offset = 34;
2111         }
2112
2113         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2114         return 0;
2115 }
2116
2117 /* These tables from cdrecord - I don't have orange book */
2118 /* standard speed CD-RW (1-4x) */
2119 static char clv_to_speed[16] = {
2120         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2121            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2122 };
2123 /* high speed CD-RW (-10x) */
2124 static char hs_clv_to_speed[16] = {
2125         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2126            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2127 };
2128 /* ultra high speed CD-RW */
2129 static char us_clv_to_speed[16] = {
2130         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2131            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2132 };
2133
2134 /*
2135  * reads the maximum media speed from ATIP
2136  */
2137 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2138                                                 unsigned *speed)
2139 {
2140         struct packet_command cgc;
2141         struct request_sense sense;
2142         unsigned char buf[64];
2143         unsigned int size, st, sp;
2144         int ret;
2145
2146         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2147         cgc.sense = &sense;
2148         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2149         cgc.cmd[1] = 2;
2150         cgc.cmd[2] = 4; /* READ ATIP */
2151         cgc.cmd[8] = 2;
2152         ret = pkt_generic_packet(pd, &cgc);
2153         if (ret) {
2154                 pkt_dump_sense(&cgc);
2155                 return ret;
2156         }
2157         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2158         if (size > sizeof(buf))
2159                 size = sizeof(buf);
2160
2161         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2162         cgc.sense = &sense;
2163         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2164         cgc.cmd[1] = 2;
2165         cgc.cmd[2] = 4;
2166         cgc.cmd[8] = size;
2167         ret = pkt_generic_packet(pd, &cgc);
2168         if (ret) {
2169                 pkt_dump_sense(&cgc);
2170                 return ret;
2171         }
2172
2173         if (!(buf[6] & 0x40)) {
2174                 printk(DRIVER_NAME": Disc type is not CD-RW\n");
2175                 return 1;
2176         }
2177         if (!(buf[6] & 0x4)) {
2178                 printk(DRIVER_NAME": A1 values on media are not valid, maybe not CDRW?\n");
2179                 return 1;
2180         }
2181
2182         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2183
2184         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2185
2186         /* Info from cdrecord */
2187         switch (st) {
2188                 case 0: /* standard speed */
2189                         *speed = clv_to_speed[sp];
2190                         break;
2191                 case 1: /* high speed */
2192                         *speed = hs_clv_to_speed[sp];
2193                         break;
2194                 case 2: /* ultra high speed */
2195                         *speed = us_clv_to_speed[sp];
2196                         break;
2197                 default:
2198                         printk(DRIVER_NAME": Unknown disc sub-type %d\n",st);
2199                         return 1;
2200         }
2201         if (*speed) {
2202                 printk(DRIVER_NAME": Max. media speed: %d\n",*speed);
2203                 return 0;
2204         } else {
2205                 printk(DRIVER_NAME": Unknown speed %d for sub-type %d\n",sp,st);
2206                 return 1;
2207         }
2208 }
2209
2210 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2211 {
2212         struct packet_command cgc;
2213         struct request_sense sense;
2214         int ret;
2215
2216         VPRINTK(DRIVER_NAME": Performing OPC\n");
2217
2218         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2219         cgc.sense = &sense;
2220         cgc.timeout = 60*HZ;
2221         cgc.cmd[0] = GPCMD_SEND_OPC;
2222         cgc.cmd[1] = 1;
2223         if ((ret = pkt_generic_packet(pd, &cgc)))
2224                 pkt_dump_sense(&cgc);
2225         return ret;
2226 }
2227
2228 static int pkt_open_write(struct pktcdvd_device *pd)
2229 {
2230         int ret;
2231         unsigned int write_speed, media_write_speed, read_speed;
2232
2233         if ((ret = pkt_probe_settings(pd))) {
2234                 VPRINTK(DRIVER_NAME": %s failed probe\n", pd->name);
2235                 return ret;
2236         }
2237
2238         if ((ret = pkt_set_write_settings(pd))) {
2239                 DPRINTK(DRIVER_NAME": %s failed saving write settings\n", pd->name);
2240                 return -EIO;
2241         }
2242
2243         pkt_write_caching(pd, USE_WCACHING);
2244
2245         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2246                 write_speed = 16 * 177;
2247         switch (pd->mmc3_profile) {
2248                 case 0x13: /* DVD-RW */
2249                 case 0x1a: /* DVD+RW */
2250                 case 0x12: /* DVD-RAM */
2251                         DPRINTK(DRIVER_NAME": write speed %ukB/s\n", write_speed);
2252                         break;
2253                 default:
2254                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2255                                 media_write_speed = 16;
2256                         write_speed = min(write_speed, media_write_speed * 177);
2257                         DPRINTK(DRIVER_NAME": write speed %ux\n", write_speed / 176);
2258                         break;
2259         }
2260         read_speed = write_speed;
2261
2262         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2263                 DPRINTK(DRIVER_NAME": %s couldn't set write speed\n", pd->name);
2264                 return -EIO;
2265         }
2266         pd->write_speed = write_speed;
2267         pd->read_speed = read_speed;
2268
2269         if ((ret = pkt_perform_opc(pd))) {
2270                 DPRINTK(DRIVER_NAME": %s Optimum Power Calibration failed\n", pd->name);
2271         }
2272
2273         return 0;
2274 }
2275
2276 /*
2277  * called at open time.
2278  */
2279 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2280 {
2281         int ret;
2282         long lba;
2283         struct request_queue *q;
2284
2285         /*
2286          * We need to re-open the cdrom device without O_NONBLOCK to be able
2287          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2288          * so bdget() can't fail.
2289          */
2290         bdget(pd->bdev->bd_dev);
2291         if ((ret = blkdev_get(pd->bdev, FMODE_READ)))
2292                 goto out;
2293
2294         if ((ret = bd_claim(pd->bdev, pd)))
2295                 goto out_putdev;
2296
2297         if ((ret = pkt_get_last_written(pd, &lba))) {
2298                 printk(DRIVER_NAME": pkt_get_last_written failed\n");
2299                 goto out_unclaim;
2300         }
2301
2302         set_capacity(pd->disk, lba << 2);
2303         set_capacity(pd->bdev->bd_disk, lba << 2);
2304         bd_set_size(pd->bdev, (loff_t)lba << 11);
2305
2306         q = bdev_get_queue(pd->bdev);
2307         if (write) {
2308                 if ((ret = pkt_open_write(pd)))
2309                         goto out_unclaim;
2310                 /*
2311                  * Some CDRW drives can not handle writes larger than one packet,
2312                  * even if the size is a multiple of the packet size.
2313                  */
2314                 spin_lock_irq(q->queue_lock);
2315                 blk_queue_max_hw_sectors(q, pd->settings.size);
2316                 spin_unlock_irq(q->queue_lock);
2317                 set_bit(PACKET_WRITABLE, &pd->flags);
2318         } else {
2319                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2320                 clear_bit(PACKET_WRITABLE, &pd->flags);
2321         }
2322
2323         if ((ret = pkt_set_segment_merging(pd, q)))
2324                 goto out_unclaim;
2325
2326         if (write) {
2327                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2328                         printk(DRIVER_NAME": not enough memory for buffers\n");
2329                         ret = -ENOMEM;
2330                         goto out_unclaim;
2331                 }
2332                 printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
2333         }
2334
2335         return 0;
2336
2337 out_unclaim:
2338         bd_release(pd->bdev);
2339 out_putdev:
2340         blkdev_put(pd->bdev, FMODE_READ);
2341 out:
2342         return ret;
2343 }
2344
2345 /*
2346  * called when the device is closed. makes sure that the device flushes
2347  * the internal cache before we close.
2348  */
2349 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2350 {
2351         if (flush && pkt_flush_cache(pd))
2352                 DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
2353
2354         pkt_lock_door(pd, 0);
2355
2356         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2357         bd_release(pd->bdev);
2358         blkdev_put(pd->bdev, FMODE_READ);
2359
2360         pkt_shrink_pktlist(pd);
2361 }
2362
2363 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
2364 {
2365         if (dev_minor >= MAX_WRITERS)
2366                 return NULL;
2367         return pkt_devs[dev_minor];
2368 }
2369
2370 static int pkt_open(struct block_device *bdev, fmode_t mode)
2371 {
2372         struct pktcdvd_device *pd = NULL;
2373         int ret;
2374
2375         VPRINTK(DRIVER_NAME": entering open\n");
2376
2377         mutex_lock(&ctl_mutex);
2378         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2379         if (!pd) {
2380                 ret = -ENODEV;
2381                 goto out;
2382         }
2383         BUG_ON(pd->refcnt < 0);
2384
2385         pd->refcnt++;
2386         if (pd->refcnt > 1) {
2387                 if ((mode & FMODE_WRITE) &&
2388                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2389                         ret = -EBUSY;
2390                         goto out_dec;
2391                 }
2392         } else {
2393                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2394                 if (ret)
2395                         goto out_dec;
2396                 /*
2397                  * needed here as well, since ext2 (among others) may change
2398                  * the blocksize at mount time
2399                  */
2400                 set_blocksize(bdev, CD_FRAMESIZE);
2401         }
2402
2403         mutex_unlock(&ctl_mutex);
2404         return 0;
2405
2406 out_dec:
2407         pd->refcnt--;
2408 out:
2409         VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
2410         mutex_unlock(&ctl_mutex);
2411         return ret;
2412 }
2413
2414 static int pkt_close(struct gendisk *disk, fmode_t mode)
2415 {
2416         struct pktcdvd_device *pd = disk->private_data;
2417         int ret = 0;
2418
2419         mutex_lock(&ctl_mutex);
2420         pd->refcnt--;
2421         BUG_ON(pd->refcnt < 0);
2422         if (pd->refcnt == 0) {
2423                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2424                 pkt_release_dev(pd, flush);
2425         }
2426         mutex_unlock(&ctl_mutex);
2427         return ret;
2428 }
2429
2430
2431 static void pkt_end_io_read_cloned(struct bio *bio, int err)
2432 {
2433         struct packet_stacked_data *psd = bio->bi_private;
2434         struct pktcdvd_device *pd = psd->pd;
2435
2436         bio_put(bio);
2437         bio_endio(psd->bio, err);
2438         mempool_free(psd, psd_pool);
2439         pkt_bio_finished(pd);
2440 }
2441
2442 static int pkt_make_request(struct request_queue *q, struct bio *bio)
2443 {
2444         struct pktcdvd_device *pd;
2445         char b[BDEVNAME_SIZE];
2446         sector_t zone;
2447         struct packet_data *pkt;
2448         int was_empty, blocked_bio;
2449         struct pkt_rb_node *node;
2450
2451         pd = q->queuedata;
2452         if (!pd) {
2453                 printk(DRIVER_NAME": %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
2454                 goto end_io;
2455         }
2456
2457         /*
2458          * Clone READ bios so we can have our own bi_end_io callback.
2459          */
2460         if (bio_data_dir(bio) == READ) {
2461                 struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2462                 struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2463
2464                 psd->pd = pd;
2465                 psd->bio = bio;
2466                 cloned_bio->bi_bdev = pd->bdev;
2467                 cloned_bio->bi_private = psd;
2468                 cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2469                 pd->stats.secs_r += bio->bi_size >> 9;
2470                 pkt_queue_bio(pd, cloned_bio);
2471                 return 0;
2472         }
2473
2474         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2475                 printk(DRIVER_NAME": WRITE for ro device %s (%llu)\n",
2476                         pd->name, (unsigned long long)bio->bi_sector);
2477                 goto end_io;
2478         }
2479
2480         if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
2481                 printk(DRIVER_NAME": wrong bio size\n");
2482                 goto end_io;
2483         }
2484
2485         blk_queue_bounce(q, &bio);
2486
2487         zone = ZONE(bio->bi_sector, pd);
2488         VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
2489                 (unsigned long long)bio->bi_sector,
2490                 (unsigned long long)(bio->bi_sector + bio_sectors(bio)));
2491
2492         /* Check if we have to split the bio */
2493         {
2494                 struct bio_pair *bp;
2495                 sector_t last_zone;
2496                 int first_sectors;
2497
2498                 last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
2499                 if (last_zone != zone) {
2500                         BUG_ON(last_zone != zone + pd->settings.size);
2501                         first_sectors = last_zone - bio->bi_sector;
2502                         bp = bio_split(bio, first_sectors);
2503                         BUG_ON(!bp);
2504                         pkt_make_request(q, &bp->bio1);
2505                         pkt_make_request(q, &bp->bio2);
2506                         bio_pair_release(bp);
2507                         return 0;
2508                 }
2509         }
2510
2511         /*
2512          * If we find a matching packet in state WAITING or READ_WAIT, we can
2513          * just append this bio to that packet.
2514          */
2515         spin_lock(&pd->cdrw.active_list_lock);
2516         blocked_bio = 0;
2517         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2518                 if (pkt->sector == zone) {
2519                         spin_lock(&pkt->lock);
2520                         if ((pkt->state == PACKET_WAITING_STATE) ||
2521                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2522                                 bio_list_add(&pkt->orig_bios, bio);
2523                                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
2524                                 if ((pkt->write_size >= pkt->frames) &&
2525                                     (pkt->state == PACKET_WAITING_STATE)) {
2526                                         atomic_inc(&pkt->run_sm);
2527                                         wake_up(&pd->wqueue);
2528                                 }
2529                                 spin_unlock(&pkt->lock);
2530                                 spin_unlock(&pd->cdrw.active_list_lock);
2531                                 return 0;
2532                         } else {
2533                                 blocked_bio = 1;
2534                         }
2535                         spin_unlock(&pkt->lock);
2536                 }
2537         }
2538         spin_unlock(&pd->cdrw.active_list_lock);
2539
2540         /*
2541          * Test if there is enough room left in the bio work queue
2542          * (queue size >= congestion on mark).
2543          * If not, wait till the work queue size is below the congestion off mark.
2544          */
2545         spin_lock(&pd->lock);
2546         if (pd->write_congestion_on > 0
2547             && pd->bio_queue_size >= pd->write_congestion_on) {
2548                 set_bdi_congested(&q->backing_dev_info, BLK_RW_ASYNC);
2549                 do {
2550                         spin_unlock(&pd->lock);
2551                         congestion_wait(BLK_RW_ASYNC, HZ);
2552                         spin_lock(&pd->lock);
2553                 } while(pd->bio_queue_size > pd->write_congestion_off);
2554         }
2555         spin_unlock(&pd->lock);
2556
2557         /*
2558          * No matching packet found. Store the bio in the work queue.
2559          */
2560         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2561         node->bio = bio;
2562         spin_lock(&pd->lock);
2563         BUG_ON(pd->bio_queue_size < 0);
2564         was_empty = (pd->bio_queue_size == 0);
2565         pkt_rbtree_insert(pd, node);
2566         spin_unlock(&pd->lock);
2567
2568         /*
2569          * Wake up the worker thread.
2570          */
2571         atomic_set(&pd->scan_queue, 1);
2572         if (was_empty) {
2573                 /* This wake_up is required for correct operation */
2574                 wake_up(&pd->wqueue);
2575         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2576                 /*
2577                  * This wake up is not required for correct operation,
2578                  * but improves performance in some cases.
2579                  */
2580                 wake_up(&pd->wqueue);
2581         }
2582         return 0;
2583 end_io:
2584         bio_io_error(bio);
2585         return 0;
2586 }
2587
2588
2589
2590 static int pkt_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2591                           struct bio_vec *bvec)
2592 {
2593         struct pktcdvd_device *pd = q->queuedata;
2594         sector_t zone = ZONE(bmd->bi_sector, pd);
2595         int used = ((bmd->bi_sector - zone) << 9) + bmd->bi_size;
2596         int remaining = (pd->settings.size << 9) - used;
2597         int remaining2;
2598
2599         /*
2600          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2601          * boundary, pkt_make_request() will split the bio.
2602          */
2603         remaining2 = PAGE_SIZE - bmd->bi_size;
2604         remaining = max(remaining, remaining2);
2605
2606         BUG_ON(remaining < 0);
2607         return remaining;
2608 }
2609
2610 static void pkt_init_queue(struct pktcdvd_device *pd)
2611 {
2612         struct request_queue *q = pd->disk->queue;
2613
2614         blk_queue_make_request(q, pkt_make_request);
2615         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2616         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2617         blk_queue_merge_bvec(q, pkt_merge_bvec);
2618         q->queuedata = pd;
2619 }
2620
2621 static int pkt_seq_show(struct seq_file *m, void *p)
2622 {
2623         struct pktcdvd_device *pd = m->private;
2624         char *msg;
2625         char bdev_buf[BDEVNAME_SIZE];
2626         int states[PACKET_NUM_STATES];
2627
2628         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2629                    bdevname(pd->bdev, bdev_buf));
2630
2631         seq_printf(m, "\nSettings:\n");
2632         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2633
2634         if (pd->settings.write_type == 0)
2635                 msg = "Packet";
2636         else
2637                 msg = "Unknown";
2638         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2639
2640         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2641         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2642
2643         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2644
2645         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2646                 msg = "Mode 1";
2647         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2648                 msg = "Mode 2";
2649         else
2650                 msg = "Unknown";
2651         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2652
2653         seq_printf(m, "\nStatistics:\n");
2654         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2655         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2656         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2657         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2658         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2659
2660         seq_printf(m, "\nMisc:\n");
2661         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2662         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2663         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2664         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2665         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2666         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2667
2668         seq_printf(m, "\nQueue state:\n");
2669         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2670         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2671         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2672
2673         pkt_count_states(pd, states);
2674         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2675                    states[0], states[1], states[2], states[3], states[4], states[5]);
2676
2677         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2678                         pd->write_congestion_off,
2679                         pd->write_congestion_on);
2680         return 0;
2681 }
2682
2683 static int pkt_seq_open(struct inode *inode, struct file *file)
2684 {
2685         return single_open(file, pkt_seq_show, PDE(inode)->data);
2686 }
2687
2688 static const struct file_operations pkt_proc_fops = {
2689         .open   = pkt_seq_open,
2690         .read   = seq_read,
2691         .llseek = seq_lseek,
2692         .release = single_release
2693 };
2694
2695 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2696 {
2697         int i;
2698         int ret = 0;
2699         char b[BDEVNAME_SIZE];
2700         struct block_device *bdev;
2701
2702         if (pd->pkt_dev == dev) {
2703                 printk(DRIVER_NAME": Recursive setup not allowed\n");
2704                 return -EBUSY;
2705         }
2706         for (i = 0; i < MAX_WRITERS; i++) {
2707                 struct pktcdvd_device *pd2 = pkt_devs[i];
2708                 if (!pd2)
2709                         continue;
2710                 if (pd2->bdev->bd_dev == dev) {
2711                         printk(DRIVER_NAME": %s already setup\n", bdevname(pd2->bdev, b));
2712                         return -EBUSY;
2713                 }
2714                 if (pd2->pkt_dev == dev) {
2715                         printk(DRIVER_NAME": Can't chain pktcdvd devices\n");
2716                         return -EBUSY;
2717                 }
2718         }
2719
2720         bdev = bdget(dev);
2721         if (!bdev)
2722                 return -ENOMEM;
2723         ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY);
2724         if (ret)
2725                 return ret;
2726
2727         /* This is safe, since we have a reference from open(). */
2728         __module_get(THIS_MODULE);
2729
2730         pd->bdev = bdev;
2731         set_blocksize(bdev, CD_FRAMESIZE);
2732
2733         pkt_init_queue(pd);
2734
2735         atomic_set(&pd->cdrw.pending_bios, 0);
2736         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2737         if (IS_ERR(pd->cdrw.thread)) {
2738                 printk(DRIVER_NAME": can't start kernel thread\n");
2739                 ret = -ENOMEM;
2740                 goto out_mem;
2741         }
2742
2743         proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2744         DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
2745         return 0;
2746
2747 out_mem:
2748         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2749         /* This is safe: open() is still holding a reference. */
2750         module_put(THIS_MODULE);
2751         return ret;
2752 }
2753
2754 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2755 {
2756         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2757
2758         VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd,
2759                 MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2760
2761         switch (cmd) {
2762         case CDROMEJECT:
2763                 /*
2764                  * The door gets locked when the device is opened, so we
2765                  * have to unlock it or else the eject command fails.
2766                  */
2767                 if (pd->refcnt == 1)
2768                         pkt_lock_door(pd, 0);
2769                 /* fallthru */
2770         /*
2771          * forward selected CDROM ioctls to CD-ROM, for UDF
2772          */
2773         case CDROMMULTISESSION:
2774         case CDROMREADTOCENTRY:
2775         case CDROM_LAST_WRITTEN:
2776         case CDROM_SEND_PACKET:
2777         case SCSI_IOCTL_SEND_COMMAND:
2778                 return __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2779
2780         default:
2781                 VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, cmd);
2782                 return -ENOTTY;
2783         }
2784
2785         return 0;
2786 }
2787
2788 static int pkt_media_changed(struct gendisk *disk)
2789 {
2790         struct pktcdvd_device *pd = disk->private_data;
2791         struct gendisk *attached_disk;
2792
2793         if (!pd)
2794                 return 0;
2795         if (!pd->bdev)
2796                 return 0;
2797         attached_disk = pd->bdev->bd_disk;
2798         if (!attached_disk)
2799                 return 0;
2800         return attached_disk->fops->media_changed(attached_disk);
2801 }
2802
2803 static const struct block_device_operations pktcdvd_ops = {
2804         .owner =                THIS_MODULE,
2805         .open =                 pkt_open,
2806         .release =              pkt_close,
2807         .locked_ioctl =         pkt_ioctl,
2808         .media_changed =        pkt_media_changed,
2809 };
2810
2811 static char *pktcdvd_devnode(struct gendisk *gd, mode_t *mode)
2812 {
2813         return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
2814 }
2815
2816 /*
2817  * Set up mapping from pktcdvd device to CD-ROM device.
2818  */
2819 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2820 {
2821         int idx;
2822         int ret = -ENOMEM;
2823         struct pktcdvd_device *pd;
2824         struct gendisk *disk;
2825
2826         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2827
2828         for (idx = 0; idx < MAX_WRITERS; idx++)
2829                 if (!pkt_devs[idx])
2830                         break;
2831         if (idx == MAX_WRITERS) {
2832                 printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
2833                 ret = -EBUSY;
2834                 goto out_mutex;
2835         }
2836
2837         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2838         if (!pd)
2839                 goto out_mutex;
2840
2841         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2842                                                   sizeof(struct pkt_rb_node));
2843         if (!pd->rb_pool)
2844                 goto out_mem;
2845
2846         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2847         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2848         spin_lock_init(&pd->cdrw.active_list_lock);
2849
2850         spin_lock_init(&pd->lock);
2851         spin_lock_init(&pd->iosched.lock);
2852         bio_list_init(&pd->iosched.read_queue);
2853         bio_list_init(&pd->iosched.write_queue);
2854         sprintf(pd->name, DRIVER_NAME"%d", idx);
2855         init_waitqueue_head(&pd->wqueue);
2856         pd->bio_queue = RB_ROOT;
2857
2858         pd->write_congestion_on  = write_congestion_on;
2859         pd->write_congestion_off = write_congestion_off;
2860
2861         disk = alloc_disk(1);
2862         if (!disk)
2863                 goto out_mem;
2864         pd->disk = disk;
2865         disk->major = pktdev_major;
2866         disk->first_minor = idx;
2867         disk->fops = &pktcdvd_ops;
2868         disk->flags = GENHD_FL_REMOVABLE;
2869         strcpy(disk->disk_name, pd->name);
2870         disk->devnode = pktcdvd_devnode;
2871         disk->private_data = pd;
2872         disk->queue = blk_alloc_queue(GFP_KERNEL);
2873         if (!disk->queue)
2874                 goto out_mem2;
2875
2876         pd->pkt_dev = MKDEV(pktdev_major, idx);
2877         ret = pkt_new_dev(pd, dev);
2878         if (ret)
2879                 goto out_new_dev;
2880
2881         add_disk(disk);
2882
2883         pkt_sysfs_dev_new(pd);
2884         pkt_debugfs_dev_new(pd);
2885
2886         pkt_devs[idx] = pd;
2887         if (pkt_dev)
2888                 *pkt_dev = pd->pkt_dev;
2889
2890         mutex_unlock(&ctl_mutex);
2891         return 0;
2892
2893 out_new_dev:
2894         blk_cleanup_queue(disk->queue);
2895 out_mem2:
2896         put_disk(disk);
2897 out_mem:
2898         if (pd->rb_pool)
2899                 mempool_destroy(pd->rb_pool);
2900         kfree(pd);
2901 out_mutex:
2902         mutex_unlock(&ctl_mutex);
2903         printk(DRIVER_NAME": setup of pktcdvd device failed\n");
2904         return ret;
2905 }
2906
2907 /*
2908  * Tear down mapping from pktcdvd device to CD-ROM device.
2909  */
2910 static int pkt_remove_dev(dev_t pkt_dev)
2911 {
2912         struct pktcdvd_device *pd;
2913         int idx;
2914         int ret = 0;
2915
2916         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2917
2918         for (idx = 0; idx < MAX_WRITERS; idx++) {
2919                 pd = pkt_devs[idx];
2920                 if (pd && (pd->pkt_dev == pkt_dev))
2921                         break;
2922         }
2923         if (idx == MAX_WRITERS) {
2924                 DPRINTK(DRIVER_NAME": dev not setup\n");
2925                 ret = -ENXIO;
2926                 goto out;
2927         }
2928
2929         if (pd->refcnt > 0) {
2930                 ret = -EBUSY;
2931                 goto out;
2932         }
2933         if (!IS_ERR(pd->cdrw.thread))
2934                 kthread_stop(pd->cdrw.thread);
2935
2936         pkt_devs[idx] = NULL;
2937
2938         pkt_debugfs_dev_remove(pd);
2939         pkt_sysfs_dev_remove(pd);
2940
2941         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2942
2943         remove_proc_entry(pd->name, pkt_proc);
2944         DPRINTK(DRIVER_NAME": writer %s unmapped\n", pd->name);
2945
2946         del_gendisk(pd->disk);
2947         blk_cleanup_queue(pd->disk->queue);
2948         put_disk(pd->disk);
2949
2950         mempool_destroy(pd->rb_pool);
2951         kfree(pd);
2952
2953         /* This is safe: open() is still holding a reference. */
2954         module_put(THIS_MODULE);
2955
2956 out:
2957         mutex_unlock(&ctl_mutex);
2958         return ret;
2959 }
2960
2961 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2962 {
2963         struct pktcdvd_device *pd;
2964
2965         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2966
2967         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2968         if (pd) {
2969                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2970                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2971         } else {
2972                 ctrl_cmd->dev = 0;
2973                 ctrl_cmd->pkt_dev = 0;
2974         }
2975         ctrl_cmd->num_devices = MAX_WRITERS;
2976
2977         mutex_unlock(&ctl_mutex);
2978 }
2979
2980 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
2981 {
2982         void __user *argp = (void __user *)arg;
2983         struct pkt_ctrl_command ctrl_cmd;
2984         int ret = 0;
2985         dev_t pkt_dev = 0;
2986
2987         if (cmd != PACKET_CTRL_CMD)
2988                 return -ENOTTY;
2989
2990         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2991                 return -EFAULT;
2992
2993         switch (ctrl_cmd.command) {
2994         case PKT_CTRL_CMD_SETUP:
2995                 if (!capable(CAP_SYS_ADMIN))
2996                         return -EPERM;
2997                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2998                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2999                 break;
3000         case PKT_CTRL_CMD_TEARDOWN:
3001                 if (!capable(CAP_SYS_ADMIN))
3002                         return -EPERM;
3003                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
3004                 break;
3005         case PKT_CTRL_CMD_STATUS:
3006                 pkt_get_status(&ctrl_cmd);
3007                 break;
3008         default:
3009                 return -ENOTTY;
3010         }
3011
3012         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
3013                 return -EFAULT;
3014         return ret;
3015 }
3016
3017
3018 static const struct file_operations pkt_ctl_fops = {
3019         .ioctl   = pkt_ctl_ioctl,
3020         .owner   = THIS_MODULE,
3021 };
3022
3023 static struct miscdevice pkt_misc = {
3024         .minor          = MISC_DYNAMIC_MINOR,
3025         .name           = DRIVER_NAME,
3026         .nodename       = "pktcdvd/control",
3027         .fops           = &pkt_ctl_fops
3028 };
3029
3030 static int __init pkt_init(void)
3031 {
3032         int ret;
3033
3034         mutex_init(&ctl_mutex);
3035
3036         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
3037                                         sizeof(struct packet_stacked_data));
3038         if (!psd_pool)
3039                 return -ENOMEM;
3040
3041         ret = register_blkdev(pktdev_major, DRIVER_NAME);
3042         if (ret < 0) {
3043                 printk(DRIVER_NAME": Unable to register block device\n");
3044                 goto out2;
3045         }
3046         if (!pktdev_major)
3047                 pktdev_major = ret;
3048
3049         ret = pkt_sysfs_init();
3050         if (ret)
3051                 goto out;
3052
3053         pkt_debugfs_init();
3054
3055         ret = misc_register(&pkt_misc);
3056         if (ret) {
3057                 printk(DRIVER_NAME": Unable to register misc device\n");
3058                 goto out_misc;
3059         }
3060
3061         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
3062
3063         return 0;
3064
3065 out_misc:
3066         pkt_debugfs_cleanup();
3067         pkt_sysfs_cleanup();
3068 out:
3069         unregister_blkdev(pktdev_major, DRIVER_NAME);
3070 out2:
3071         mempool_destroy(psd_pool);
3072         return ret;
3073 }
3074
3075 static void __exit pkt_exit(void)
3076 {
3077         remove_proc_entry("driver/"DRIVER_NAME, NULL);
3078         misc_deregister(&pkt_misc);
3079
3080         pkt_debugfs_cleanup();
3081         pkt_sysfs_cleanup();
3082
3083         unregister_blkdev(pktdev_major, DRIVER_NAME);
3084         mempool_destroy(psd_pool);
3085 }
3086
3087 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3088 MODULE_AUTHOR("Jens Axboe <[email protected]>");
3089 MODULE_LICENSE("GPL");
3090
3091 module_init(pkt_init);
3092 module_exit(pkt_exit);