drivers/block/pktcdvd.c

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   4  * Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
   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; /* /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         p = kzalloc(sizeof(*p), GFP_KERNEL);
 114         if (!p)
 115                 return NULL;
 116         kobject_set_name(&p->kobj, "%s", name);
 117         p->kobj.parent = parent;
 118         p->kobj.ktype = ktype;
 119         p->pd = pd;
 120         if (kobject_register(&p->kobj) != 0)
 121                 return NULL;
 122         return p;
 123 }
 124 /*
 125  * remove a pktcdvd kernel object.
 126  */
 127 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
 128 {
 129         if (p)
 130                 kobject_unregister(&p->kobj);
 131 }
 132 /*
 133  * default release function for pktcdvd kernel objects.
 134  */
 135 static void pkt_kobj_release(struct kobject *kobj)
 136 {
 137         kfree(to_pktcdvdkobj(kobj));
 138 }
 139
 140
 141 /**********************************************************
 142  *
 143  * sysfs interface for pktcdvd
 144  * by (C) 2006  Thomas Maier <balagi@justmail.de>
 145  *
 146  **********************************************************/
 147
 148 #define DEF_ATTR(_obj,_name,_mode) \
 149         static struct attribute _obj = { .name = _name, .mode = _mode }
 150
 151 /**********************************************************
 152   /sys/class/pktcdvd/pktcdvd[0-7]/
 153                      stat/reset
 154                      stat/packets_started
 155                      stat/packets_finished
 156                      stat/kb_written
 157                      stat/kb_read
 158                      stat/kb_read_gather
 159                      write_queue/size
 160                      write_queue/congestion_off
 161                      write_queue/congestion_on
 162  **********************************************************/
 163
 164 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
 165 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
 166 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
 167 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
 168 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
 169 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
 170
 171 static struct attribute *kobj_pkt_attrs_stat[] = {
 172         &kobj_pkt_attr_st1,
 173         &kobj_pkt_attr_st2,
 174         &kobj_pkt_attr_st3,
 175         &kobj_pkt_attr_st4,
 176         &kobj_pkt_attr_st5,
 177         &kobj_pkt_attr_st6,
 178         NULL
 179 };
 180
 181 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
 182 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
 183 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
 184
 185 static struct attribute *kobj_pkt_attrs_wqueue[] = {
 186         &kobj_pkt_attr_wq1,
 187         &kobj_pkt_attr_wq2,
 188         &kobj_pkt_attr_wq3,
 189         NULL
 190 };
 191
 192 static ssize_t kobj_pkt_show(struct kobject *kobj,
 193                         struct attribute *attr, char *data)
 194 {
 195         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 196         int n = 0;
 197         int v;
 198         if (strcmp(attr->name, "packets_started") == 0) {
 199                 n = sprintf(data, "%lu\n", pd->stats.pkt_started);
 200
 201         } else if (strcmp(attr->name, "packets_finished") == 0) {
 202                 n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
 203
 204         } else if (strcmp(attr->name, "kb_written") == 0) {
 205                 n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
 206
 207         } else if (strcmp(attr->name, "kb_read") == 0) {
 208                 n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
 209
 210         } else if (strcmp(attr->name, "kb_read_gather") == 0) {
 211                 n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
 212
 213         } else if (strcmp(attr->name, "size") == 0) {
 214                 spin_lock(&pd->lock);
 215                 v = pd->bio_queue_size;
 216                 spin_unlock(&pd->lock);
 217                 n = sprintf(data, "%d\n", v);
 218
 219         } else if (strcmp(attr->name, "congestion_off") == 0) {
 220                 spin_lock(&pd->lock);
 221                 v = pd->write_congestion_off;
 222                 spin_unlock(&pd->lock);
 223                 n = sprintf(data, "%d\n", v);
 224
 225         } else if (strcmp(attr->name, "congestion_on") == 0) {
 226                 spin_lock(&pd->lock);
 227                 v = pd->write_congestion_on;
 228                 spin_unlock(&pd->lock);
 229                 n = sprintf(data, "%d\n", v);
 230         }
 231         return n;
 232 }
 233
 234 static void init_write_congestion_marks(int* lo, int* hi)
 235 {
 236         if (*hi > 0) {
 237                 *hi = max(*hi, 500);
 238                 *hi = min(*hi, 1000000);
 239                 if (*lo <= 0)
 240                         *lo = *hi - 100;
 241                 else {
 242                         *lo = min(*lo, *hi - 100);
 243                         *lo = max(*lo, 100);
 244                 }
 245         } else {
 246                 *hi = -1;
 247                 *lo = -1;
 248         }
 249 }
 250
 251 static ssize_t kobj_pkt_store(struct kobject *kobj,
 252                         struct attribute *attr,
 253                         const char *data, size_t len)
 254 {
 255         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 256         int val;
 257
 258         if (strcmp(attr->name, "reset") == 0 && len > 0) {
 259                 pd->stats.pkt_started = 0;
 260                 pd->stats.pkt_ended = 0;
 261                 pd->stats.secs_w = 0;
 262                 pd->stats.secs_rg = 0;
 263                 pd->stats.secs_r = 0;
 264
 265         } else if (strcmp(attr->name, "congestion_off") == 0
 266                    && sscanf(data, "%d", &val) == 1) {
 267                 spin_lock(&pd->lock);
 268                 pd->write_congestion_off = val;
 269                 init_write_congestion_marks(&pd->write_congestion_off,
 270                                         &pd->write_congestion_on);
 271                 spin_unlock(&pd->lock);
 272
 273         } else if (strcmp(attr->name, "congestion_on") == 0
 274                    && sscanf(data, "%d", &val) == 1) {
 275                 spin_lock(&pd->lock);
 276                 pd->write_congestion_on = val;
 277                 init_write_congestion_marks(&pd->write_congestion_off,
 278                                         &pd->write_congestion_on);
 279                 spin_unlock(&pd->lock);
 280         }
 281         return len;
 282 }
 283
 284 static struct sysfs_ops kobj_pkt_ops = {
 285         .show = kobj_pkt_show,
 286         .store = kobj_pkt_store
 287 };
 288 static struct kobj_type kobj_pkt_type_stat = {
 289         .release = pkt_kobj_release,
 290         .sysfs_ops = &kobj_pkt_ops,
 291         .default_attrs = kobj_pkt_attrs_stat
 292 };
 293 static struct kobj_type kobj_pkt_type_wqueue = {
 294         .release = pkt_kobj_release,
 295         .sysfs_ops = &kobj_pkt_ops,
 296         .default_attrs = kobj_pkt_attrs_wqueue
 297 };
 298
 299 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 300 {
 301         if (class_pktcdvd) {
 302                 pd->clsdev = class_device_create(class_pktcdvd,
 303                                         NULL, pd->pkt_dev,
 304                                         NULL, "%s", pd->name);
 305                 if (IS_ERR(pd->clsdev))
 306                         pd->clsdev = NULL;
 307         }
 308         if (pd->clsdev) {
 309                 pd->kobj_stat = pkt_kobj_create(pd, "stat",
 310                                         &pd->clsdev->kobj,
 311                                         &kobj_pkt_type_stat);
 312                 pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
 313                                         &pd->clsdev->kobj,
 314                                         &kobj_pkt_type_wqueue);
 315         }
 316 }
 317
 318 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 319 {
 320         pkt_kobj_remove(pd->kobj_stat);
 321         pkt_kobj_remove(pd->kobj_wqueue);
 322         if (class_pktcdvd)
 323                 class_device_destroy(class_pktcdvd, pd->pkt_dev);
 324 }
 325
 326
 327 /********************************************************************
 328   /sys/class/pktcdvd/
 329                      add            map block device
 330                      remove         unmap packet dev
 331                      device_map     show mappings
 332  *******************************************************************/
 333
 334 static void class_pktcdvd_release(struct class *cls)
 335 {
 336         kfree(cls);
 337 }
 338 static ssize_t class_pktcdvd_show_map(struct class *c, char *data)
 339 {
 340         int n = 0;
 341         int idx;
 342         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 343         for (idx = 0; idx < MAX_WRITERS; idx++) {
 344                 struct pktcdvd_device *pd = pkt_devs[idx];
 345                 if (!pd)
 346                         continue;
 347                 n += sprintf(data+n, "%s %u:%u %u:%u\n",
 348                         pd->name,
 349                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 350                         MAJOR(pd->bdev->bd_dev),
 351                         MINOR(pd->bdev->bd_dev));
 352         }
 353         mutex_unlock(&ctl_mutex);
 354         return n;
 355 }
 356
 357 static ssize_t class_pktcdvd_store_add(struct class *c, const char *buf,
 358                                         size_t count)
 359 {
 360         unsigned int major, minor;
 361         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 362                 pkt_setup_dev(MKDEV(major, minor), NULL);
 363                 return count;
 364         }
 365         return -EINVAL;
 366 }
 367
 368 static ssize_t class_pktcdvd_store_remove(struct class *c, const char *buf,
 369                                         size_t count)
 370 {
 371         unsigned int major, minor;
 372         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 373                 pkt_remove_dev(MKDEV(major, minor));
 374                 return count;
 375         }
 376         return -EINVAL;
 377 }
 378
 379 static struct class_attribute class_pktcdvd_attrs[] = {
 380  __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
 381  __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
 382  __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
 383  __ATTR_NULL
 384 };
 385
 386
 387 static int pkt_sysfs_init(void)
 388 {
 389         int ret = 0;
 390
 391         /*
 392          * create control files in sysfs
 393          * /sys/class/pktcdvd/...
 394          */
 395         class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
 396         if (!class_pktcdvd)
 397                 return -ENOMEM;
 398         class_pktcdvd->name = DRIVER_NAME;
 399         class_pktcdvd->owner = THIS_MODULE;
 400         class_pktcdvd->class_release = class_pktcdvd_release;
 401         class_pktcdvd->class_attrs = class_pktcdvd_attrs;
 402         ret = class_register(class_pktcdvd);
 403         if (ret) {
 404                 kfree(class_pktcdvd);
 405                 class_pktcdvd = NULL;
 406                 printk(DRIVER_NAME": failed to create class pktcdvd\n");
 407                 return ret;
 408         }
 409         return 0;
 410 }
 411
 412 static void pkt_sysfs_cleanup(void)
 413 {
 414         if (class_pktcdvd)
 415                 class_destroy(class_pktcdvd);
 416         class_pktcdvd = NULL;
 417 }
 418
 419 /********************************************************************
 420   entries in debugfs
 421
 422   /debugfs/pktcdvd[0-7]/
 423                         info
 424
 425  *******************************************************************/
 426
 427 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
 428 {
 429         return pkt_seq_show(m, p);
 430 }
 431
 432 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
 433 {
 434         return single_open(file, pkt_debugfs_seq_show, inode->i_private);
 435 }
 436
 437 static const struct file_operations debug_fops = {
 438         .open           = pkt_debugfs_fops_open,
 439         .read           = seq_read,
 440         .llseek         = seq_lseek,
 441         .release        = single_release,
 442         .owner          = THIS_MODULE,
 443 };
 444
 445 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 446 {
 447         if (!pkt_debugfs_root)
 448                 return;
 449         pd->dfs_f_info = NULL;
 450         pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
 451         if (IS_ERR(pd->dfs_d_root)) {
 452                 pd->dfs_d_root = NULL;
 453                 return;
 454         }
 455         pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
 456                                 pd->dfs_d_root, pd, &debug_fops);
 457         if (IS_ERR(pd->dfs_f_info)) {
 458                 pd->dfs_f_info = NULL;
 459                 return;
 460         }
 461 }
 462
 463 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
 464 {
 465         if (!pkt_debugfs_root)
 466                 return;
 467         if (pd->dfs_f_info)
 468                 debugfs_remove(pd->dfs_f_info);
 469         pd->dfs_f_info = NULL;
 470         if (pd->dfs_d_root)
 471                 debugfs_remove(pd->dfs_d_root);
 472         pd->dfs_d_root = NULL;
 473 }
 474
 475 static void pkt_debugfs_init(void)
 476 {
 477         pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
 478         if (IS_ERR(pkt_debugfs_root)) {
 479                 pkt_debugfs_root = NULL;
 480                 return;
 481         }
 482 }
 483
 484 static void pkt_debugfs_cleanup(void)
 485 {
 486         if (!pkt_debugfs_root)
 487                 return;
 488         debugfs_remove(pkt_debugfs_root);
 489         pkt_debugfs_root = NULL;
 490 }
 491
 492 /* ----------------------------------------------------------*/
 493
 494
 495 static void pkt_bio_finished(struct pktcdvd_device *pd)
 496 {
 497         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
 498         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
 499                 VPRINTK(DRIVER_NAME": queue empty\n");
 500                 atomic_set(&pd->iosched.attention, 1);
 501                 wake_up(&pd->wqueue);
 502         }
 503 }
 504
 505 static void pkt_bio_destructor(struct bio *bio)
 506 {
 507         kfree(bio->bi_io_vec);
 508         kfree(bio);
 509 }
 510
 511 static struct bio *pkt_bio_alloc(int nr_iovecs)
 512 {
 513         struct bio_vec *bvl = NULL;
 514         struct bio *bio;
 515
 516         bio = kmalloc(sizeof(struct bio), GFP_KERNEL);
 517         if (!bio)
 518                 goto no_bio;
 519         bio_init(bio);
 520
 521         bvl = kcalloc(nr_iovecs, sizeof(struct bio_vec), GFP_KERNEL);
 522         if (!bvl)
 523                 goto no_bvl;
 524
 525         bio->bi_max_vecs = nr_iovecs;
 526         bio->bi_io_vec = bvl;
 527         bio->bi_destructor = pkt_bio_destructor;
 528
 529         return bio;
 530
 531  no_bvl:
 532         kfree(bio);
 533  no_bio:
 534         return NULL;
 535 }
 536
 537 /*
 538  * Allocate a packet_data struct
 539  */
 540 static struct packet_data *pkt_alloc_packet_data(int frames)
 541 {
 542         int i;
 543         struct packet_data *pkt;
 544
 545         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 546         if (!pkt)
 547                 goto no_pkt;
 548
 549         pkt->frames = frames;
 550         pkt->w_bio = pkt_bio_alloc(frames);
 551         if (!pkt->w_bio)
 552                 goto no_bio;
 553
 554         for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 555                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 556                 if (!pkt->pages[i])
 557                         goto no_page;
 558         }
 559
 560         spin_lock_init(&pkt->lock);
 561
 562         for (i = 0; i < frames; i++) {
 563                 struct bio *bio = pkt_bio_alloc(1);
 564                 if (!bio)
 565                         goto no_rd_bio;
 566                 pkt->r_bios[i] = bio;
 567         }
 568
 569         return pkt;
 570
 571 no_rd_bio:
 572         for (i = 0; i < frames; i++) {
 573                 struct bio *bio = pkt->r_bios[i];
 574                 if (bio)
 575                         bio_put(bio);
 576         }
 577
 578 no_page:
 579         for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 580                 if (pkt->pages[i])
 581                         __free_page(pkt->pages[i]);
 582         bio_put(pkt->w_bio);
 583 no_bio:
 584         kfree(pkt);
 585 no_pkt:
 586         return NULL;
 587 }
 588
 589 /*
 590  * Free a packet_data struct
 591  */
 592 static void pkt_free_packet_data(struct packet_data *pkt)
 593 {
 594         int i;
 595
 596         for (i = 0; i < pkt->frames; i++) {
 597                 struct bio *bio = pkt->r_bios[i];
 598                 if (bio)
 599                         bio_put(bio);
 600         }
 601         for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 602                 __free_page(pkt->pages[i]);
 603         bio_put(pkt->w_bio);
 604         kfree(pkt);
 605 }
 606
 607 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 608 {
 609         struct packet_data *pkt, *next;
 610
 611         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 612
 613         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 614                 pkt_free_packet_data(pkt);
 615         }
 616         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 617 }
 618
 619 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 620 {
 621         struct packet_data *pkt;
 622
 623         BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
 624
 625         while (nr_packets > 0) {
 626                 pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 627                 if (!pkt) {
 628                         pkt_shrink_pktlist(pd);
 629                         return 0;
 630                 }
 631                 pkt->id = nr_packets;
 632                 pkt->pd = pd;
 633                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 634                 nr_packets--;
 635         }
 636         return 1;
 637 }
 638
 639 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 640 {
 641         struct rb_node *n = rb_next(&node->rb_node);
 642         if (!n)
 643                 return NULL;
 644         return rb_entry(n, struct pkt_rb_node, rb_node);
 645 }
 646
 647 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 648 {
 649         rb_erase(&node->rb_node, &pd->bio_queue);
 650         mempool_free(node, pd->rb_pool);
 651         pd->bio_queue_size--;
 652         BUG_ON(pd->bio_queue_size < 0);
 653 }
 654
 655 /*
 656  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 657  */
 658 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 659 {
 660         struct rb_node *n = pd->bio_queue.rb_node;
 661         struct rb_node *next;
 662         struct pkt_rb_node *tmp;
 663
 664         if (!n) {
 665                 BUG_ON(pd->bio_queue_size > 0);
 666                 return NULL;
 667         }
 668
 669         for (;;) {
 670                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 671                 if (s <= tmp->bio->bi_sector)
 672                         next = n->rb_left;
 673                 else
 674                         next = n->rb_right;
 675                 if (!next)
 676                         break;
 677                 n = next;
 678         }
 679
 680         if (s > tmp->bio->bi_sector) {
 681                 tmp = pkt_rbtree_next(tmp);
 682                 if (!tmp)
 683                         return NULL;
 684         }
 685         BUG_ON(s > tmp->bio->bi_sector);
 686         return tmp;
 687 }
 688
 689 /*
 690  * Insert a node into the pd->bio_queue rb tree.
 691  */
 692 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 693 {
 694         struct rb_node **p = &pd->bio_queue.rb_node;
 695         struct rb_node *parent = NULL;
 696         sector_t s = node->bio->bi_sector;
 697         struct pkt_rb_node *tmp;
 698
 699         while (*p) {
 700                 parent = *p;
 701                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 702                 if (s < tmp->bio->bi_sector)
 703                         p = &(*p)->rb_left;
 704                 else
 705                         p = &(*p)->rb_right;
 706         }
 707         rb_link_node(&node->rb_node, parent, p);
 708         rb_insert_color(&node->rb_node, &pd->bio_queue);
 709         pd->bio_queue_size++;
 710 }
 711
 712 /*
 713  * Add a bio to a single linked list defined by its head and tail pointers.
 714  */
 715 static void pkt_add_list_last(struct bio *bio, struct bio **list_head, struct bio **list_tail)
 716 {
 717         bio->bi_next = NULL;
 718         if (*list_tail) {
 719                 BUG_ON((*list_head) == NULL);
 720                 (*list_tail)->bi_next = bio;
 721                 (*list_tail) = bio;
 722         } else {
 723                 BUG_ON((*list_head) != NULL);
 724                 (*list_head) = bio;
 725                 (*list_tail) = bio;
 726         }
 727 }
 728
 729 /*
 730  * Remove and return the first bio from a single linked list defined by its
 731  * head and tail pointers.
 732  */
 733 static inline struct bio *pkt_get_list_first(struct bio **list_head, struct bio **list_tail)
 734 {
 735         struct bio *bio;
 736
 737         if (*list_head == NULL)
 738                 return NULL;
 739
 740         bio = *list_head;
 741         *list_head = bio->bi_next;
 742         if (*list_head == NULL)
 743                 *list_tail = NULL;
 744
 745         bio->bi_next = NULL;
 746         return bio;
 747 }
 748
 749 /*
 750  * Send a packet_command to the underlying block device and
 751  * wait for completion.
 752  */
 753 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 754 {
 755         struct request_queue *q = bdev_get_queue(pd->bdev);
 756         struct request *rq;
 757         int ret = 0;
 758
 759         rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 760                              WRITE : READ, __GFP_WAIT);
 761
 762         if (cgc->buflen) {
 763                 if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
 764                         goto out;
 765         }
 766
 767         rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 768         memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 769         if (sizeof(rq->cmd) > CDROM_PACKET_SIZE)
 770                 memset(rq->cmd + CDROM_PACKET_SIZE, 0, sizeof(rq->cmd) - CDROM_PACKET_SIZE);
 771
 772         rq->timeout = 60*HZ;
 773         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 774         rq->cmd_flags |= REQ_HARDBARRIER;
 775         if (cgc->quiet)
 776                 rq->cmd_flags |= REQ_QUIET;
 777
 778         blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
 779         if (rq->errors)
 780                 ret = -EIO;
 781 out:
 782         blk_put_request(rq);
 783         return ret;
 784 }
 785
 786 /*
 787  * A generic sense dump / resolve mechanism should be implemented across
 788  * all ATAPI + SCSI devices.
 789  */
 790 static void pkt_dump_sense(struct packet_command *cgc)
 791 {
 792         static char *info[9] = { "No sense", "Recovered error", "Not ready",
 793                                  "Medium error", "Hardware error", "Illegal request",
 794                                  "Unit attention", "Data protect", "Blank check" };
 795         int i;
 796         struct request_sense *sense = cgc->sense;
 797
 798         printk(DRIVER_NAME":");
 799         for (i = 0; i < CDROM_PACKET_SIZE; i++)
 800                 printk(" %02x", cgc->cmd[i]);
 801         printk(" - ");
 802
 803         if (sense == NULL) {
 804                 printk("no sense\n");
 805                 return;
 806         }
 807
 808         printk("sense %02x.%02x.%02x", sense->sense_key, sense->asc, sense->ascq);
 809
 810         if (sense->sense_key > 8) {
 811                 printk(" (INVALID)\n");
 812                 return;
 813         }
 814
 815         printk(" (%s)\n", info[sense->sense_key]);
 816 }
 817
 818 /*
 819  * flush the drive cache to media
 820  */
 821 static int pkt_flush_cache(struct pktcdvd_device *pd)
 822 {
 823         struct packet_command cgc;
 824
 825         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 826         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 827         cgc.quiet = 1;
 828
 829         /*
 830          * the IMMED bit -- we default to not setting it, although that
 831          * would allow a much faster close, this is safer
 832          */
 833 #if 0
 834         cgc.cmd[1] = 1 << 1;
 835 #endif
 836         return pkt_generic_packet(pd, &cgc);
 837 }
 838
 839 /*
 840  * speed is given as the normal factor, e.g. 4 for 4x
 841  */
 842 static int pkt_set_speed(struct pktcdvd_device *pd, unsigned write_speed, unsigned read_speed)
 843 {
 844         struct packet_command cgc;
 845         struct request_sense sense;
 846         int ret;
 847
 848         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 849         cgc.sense = &sense;
 850         cgc.cmd[0] = GPCMD_SET_SPEED;
 851         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 852         cgc.cmd[3] = read_speed & 0xff;
 853         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 854         cgc.cmd[5] = write_speed & 0xff;
 855
 856         if ((ret = pkt_generic_packet(pd, &cgc)))
 857                 pkt_dump_sense(&cgc);
 858
 859         return ret;
 860 }
 861
 862 /*
 863  * Queue a bio for processing by the low-level CD device. Must be called
 864  * from process context.
 865  */
 866 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 867 {
 868         spin_lock(&pd->iosched.lock);
 869         if (bio_data_dir(bio) == READ) {
 870                 pkt_add_list_last(bio, &pd->iosched.read_queue,
 871                                   &pd->iosched.read_queue_tail);
 872         } else {
 873                 pkt_add_list_last(bio, &pd->iosched.write_queue,
 874                                   &pd->iosched.write_queue_tail);
 875         }
 876         spin_unlock(&pd->iosched.lock);
 877
 878         atomic_set(&pd->iosched.attention, 1);
 879         wake_up(&pd->wqueue);
 880 }
 881
 882 /*
 883  * Process the queued read/write requests. This function handles special
 884  * requirements for CDRW drives:
 885  * - A cache flush command must be inserted before a read request if the
 886  *   previous request was a write.
 887  * - Switching between reading and writing is slow, so don't do it more often
 888  *   than necessary.
 889  * - Optimize for throughput at the expense of latency. This means that streaming
 890  *   writes will never be interrupted by a read, but if the drive has to seek
 891  *   before the next write, switch to reading instead if there are any pending
 892  *   read requests.
 893  * - Set the read speed according to current usage pattern. When only reading
 894  *   from the device, it's best to use the highest possible read speed, but
 895  *   when switching often between reading and writing, it's better to have the
 896  *   same read and write speeds.
 897  */
 898 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 899 {
 900
 901         if (atomic_read(&pd->iosched.attention) == 0)
 902                 return;
 903         atomic_set(&pd->iosched.attention, 0);
 904
 905         for (;;) {
 906                 struct bio *bio;
 907                 int reads_queued, writes_queued;
 908
 909                 spin_lock(&pd->iosched.lock);
 910                 reads_queued = (pd->iosched.read_queue != NULL);
 911                 writes_queued = (pd->iosched.write_queue != NULL);
 912                 spin_unlock(&pd->iosched.lock);
 913
 914                 if (!reads_queued && !writes_queued)
 915                         break;
 916
 917                 if (pd->iosched.writing) {
 918                         int need_write_seek = 1;
 919                         spin_lock(&pd->iosched.lock);
 920                         bio = pd->iosched.write_queue;
 921                         spin_unlock(&pd->iosched.lock);
 922                         if (bio && (bio->bi_sector == pd->iosched.last_write))
 923                                 need_write_seek = 0;
 924                         if (need_write_seek && reads_queued) {
 925                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 926                                         VPRINTK(DRIVER_NAME": write, waiting\n");
 927                                         break;
 928                                 }
 929                                 pkt_flush_cache(pd);
 930                                 pd->iosched.writing = 0;
 931                         }
 932                 } else {
 933                         if (!reads_queued && writes_queued) {
 934                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 935                                         VPRINTK(DRIVER_NAME": read, waiting\n");
 936                                         break;
 937                                 }
 938                                 pd->iosched.writing = 1;
 939                         }
 940                 }
 941
 942                 spin_lock(&pd->iosched.lock);
 943                 if (pd->iosched.writing) {
 944                         bio = pkt_get_list_first(&pd->iosched.write_queue,
 945                                                  &pd->iosched.write_queue_tail);
 946                 } else {
 947                         bio = pkt_get_list_first(&pd->iosched.read_queue,
 948                                                  &pd->iosched.read_queue_tail);
 949                 }
 950                 spin_unlock(&pd->iosched.lock);
 951
 952                 if (!bio)
 953                         continue;
 954
 955                 if (bio_data_dir(bio) == READ)
 956                         pd->iosched.successive_reads += bio->bi_size >> 10;
 957                 else {
 958                         pd->iosched.successive_reads = 0;
 959                         pd->iosched.last_write = bio->bi_sector + bio_sectors(bio);
 960                 }
 961                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 962                         if (pd->read_speed == pd->write_speed) {
 963                                 pd->read_speed = MAX_SPEED;
 964                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 965                         }
 966                 } else {
 967                         if (pd->read_speed != pd->write_speed) {
 968                                 pd->read_speed = pd->write_speed;
 969                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 970                         }
 971                 }
 972
 973                 atomic_inc(&pd->cdrw.pending_bios);
 974                 generic_make_request(bio);
 975         }
 976 }
 977
 978 /*
 979  * Special care is needed if the underlying block device has a small
 980  * max_phys_segments value.
 981  */
 982 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 983 {
 984         if ((pd->settings.size << 9) / CD_FRAMESIZE <= q->max_phys_segments) {
 985                 /*
 986                  * The cdrom device can handle one segment/frame
 987                  */
 988                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 989                 return 0;
 990         } else if ((pd->settings.size << 9) / PAGE_SIZE <= q->max_phys_segments) {
 991                 /*
 992                  * We can handle this case at the expense of some extra memory
 993                  * copies during write operations
 994                  */
 995                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 996                 return 0;
 997         } else {
 998                 printk(DRIVER_NAME": cdrom max_phys_segments too small\n");
 999                 return -EIO;
1000         }
1001 }
1002
1003 /*
1004  * Copy CD_FRAMESIZE bytes from src_bio into a destination page
1005  */
1006 static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
1007 {
1008         unsigned int copy_size = CD_FRAMESIZE;
1009
1010         while (copy_size > 0) {
1011                 struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
1012                 void *vfrom = kmap_atomic(src_bvl->bv_page, KM_USER0) +
1013                         src_bvl->bv_offset + offs;
1014                 void *vto = page_address(dst_page) + dst_offs;
1015                 int len = min_t(int, copy_size, src_bvl->bv_len - offs);
1016
1017                 BUG_ON(len < 0);
1018                 memcpy(vto, vfrom, len);
1019                 kunmap_atomic(vfrom, KM_USER0);
1020
1021                 seg++;
1022                 offs = 0;
1023                 dst_offs += len;
1024                 copy_size -= len;
1025         }
1026 }
1027
1028 /*
1029  * Copy all data for this packet to pkt->pages[], so that
1030  * a) The number of required segments for the write bio is minimized, which
1031  *    is necessary for some scsi controllers.
1032  * b) The data can be used as cache to avoid read requests if we receive a
1033  *    new write request for the same zone.
1034  */
1035 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
1036 {
1037         int f, p, offs;
1038
1039         /* Copy all data to pkt->pages[] */
1040         p = 0;
1041         offs = 0;
1042         for (f = 0; f < pkt->frames; f++) {
1043                 if (bvec[f].bv_page != pkt->pages[p]) {
1044                         void *vfrom = kmap_atomic(bvec[f].bv_page, KM_USER0) + bvec[f].bv_offset;
1045                         void *vto = page_address(pkt->pages[p]) + offs;
1046                         memcpy(vto, vfrom, CD_FRAMESIZE);
1047                         kunmap_atomic(vfrom, KM_USER0);
1048                         bvec[f].bv_page = pkt->pages[p];
1049                         bvec[f].bv_offset = offs;
1050                 } else {
1051                         BUG_ON(bvec[f].bv_offset != offs);
1052                 }
1053                 offs += CD_FRAMESIZE;
1054                 if (offs >= PAGE_SIZE) {
1055                         offs = 0;
1056                         p++;
1057                 }
1058         }
1059 }
1060
1061 static int pkt_end_io_read(struct bio *bio, unsigned int bytes_done, int err)
1062 {
1063         struct packet_data *pkt = bio->bi_private;
1064         struct pktcdvd_device *pd = pkt->pd;
1065         BUG_ON(!pd);
1066
1067         if (bio->bi_size)
1068                 return 1;
1069
1070         VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
1071                 (unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
1072
1073         if (err)
1074                 atomic_inc(&pkt->io_errors);
1075         if (atomic_dec_and_test(&pkt->io_wait)) {
1076                 atomic_inc(&pkt->run_sm);
1077                 wake_up(&pd->wqueue);
1078         }
1079         pkt_bio_finished(pd);
1080
1081         return 0;
1082 }
1083
1084 static int pkt_end_io_packet_write(struct bio *bio, unsigned int bytes_done, int err)
1085 {
1086         struct packet_data *pkt = bio->bi_private;
1087         struct pktcdvd_device *pd = pkt->pd;
1088         BUG_ON(!pd);
1089
1090         if (bio->bi_size)
1091                 return 1;
1092
1093         VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
1094
1095         pd->stats.pkt_ended++;
1096
1097         pkt_bio_finished(pd);
1098         atomic_dec(&pkt->io_wait);
1099         atomic_inc(&pkt->run_sm);
1100         wake_up(&pd->wqueue);
1101         return 0;
1102 }
1103
1104 /*
1105  * Schedule reads for the holes in a packet
1106  */
1107 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1108 {
1109         int frames_read = 0;
1110         struct bio *bio;
1111         int f;
1112         char written[PACKET_MAX_SIZE];
1113
1114         BUG_ON(!pkt->orig_bios);
1115
1116         atomic_set(&pkt->io_wait, 0);
1117         atomic_set(&pkt->io_errors, 0);
1118
1119         /*
1120          * Figure out which frames we need to read before we can write.
1121          */
1122         memset(written, 0, sizeof(written));
1123         spin_lock(&pkt->lock);
1124         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1125                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1126                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1127                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1128                 BUG_ON(first_frame < 0);
1129                 BUG_ON(first_frame + num_frames > pkt->frames);
1130                 for (f = first_frame; f < first_frame + num_frames; f++)
1131                         written[f] = 1;
1132         }
1133         spin_unlock(&pkt->lock);
1134
1135         if (pkt->cache_valid) {
1136                 VPRINTK("pkt_gather_data: zone %llx cached\n",
1137                         (unsigned long long)pkt->sector);
1138                 goto out_account;
1139         }
1140
1141         /*
1142          * Schedule reads for missing parts of the packet.
1143          */
1144         for (f = 0; f < pkt->frames; f++) {
1145                 int p, offset;
1146                 if (written[f])
1147                         continue;
1148                 bio = pkt->r_bios[f];
1149                 bio_init(bio);
1150                 bio->bi_max_vecs = 1;
1151                 bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1152                 bio->bi_bdev = pd->bdev;
1153                 bio->bi_end_io = pkt_end_io_read;
1154                 bio->bi_private = pkt;
1155
1156                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1157                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1158                 VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
1159                         f, pkt->pages[p], offset);
1160                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1161                         BUG();
1162
1163                 atomic_inc(&pkt->io_wait);
1164                 bio->bi_rw = READ;
1165                 pkt_queue_bio(pd, bio);
1166                 frames_read++;
1167         }
1168
1169 out_account:
1170         VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
1171                 frames_read, (unsigned long long)pkt->sector);
1172         pd->stats.pkt_started++;
1173         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1174 }
1175
1176 /*
1177  * Find a packet matching zone, or the least recently used packet if
1178  * there is no match.
1179  */
1180 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1181 {
1182         struct packet_data *pkt;
1183
1184         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1185                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1186                         list_del_init(&pkt->list);
1187                         if (pkt->sector != zone)
1188                                 pkt->cache_valid = 0;
1189                         return pkt;
1190                 }
1191         }
1192         BUG();
1193         return NULL;
1194 }
1195
1196 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1197 {
1198         if (pkt->cache_valid) {
1199                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1200         } else {
1201                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1202         }
1203 }
1204
1205 /*
1206  * recover a failed write, query for relocation if possible
1207  *
1208  * returns 1 if recovery is possible, or 0 if not
1209  *
1210  */
1211 static int pkt_start_recovery(struct packet_data *pkt)
1212 {
1213         /*
1214          * FIXME. We need help from the file system to implement
1215          * recovery handling.
1216          */
1217         return 0;
1218 #if 0
1219         struct request *rq = pkt->rq;
1220         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1221         struct block_device *pkt_bdev;
1222         struct super_block *sb = NULL;
1223         unsigned long old_block, new_block;
1224         sector_t new_sector;
1225
1226         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1227         if (pkt_bdev) {
1228                 sb = get_super(pkt_bdev);
1229                 bdput(pkt_bdev);
1230         }
1231
1232         if (!sb)
1233                 return 0;
1234
1235         if (!sb->s_op || !sb->s_op->relocate_blocks)
1236                 goto out;
1237
1238         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1239         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1240                 goto out;
1241
1242         new_sector = new_block * (CD_FRAMESIZE >> 9);
1243         pkt->sector = new_sector;
1244
1245         pkt->bio->bi_sector = new_sector;
1246         pkt->bio->bi_next = NULL;
1247         pkt->bio->bi_flags = 1 << BIO_UPTODATE;
1248         pkt->bio->bi_idx = 0;
1249
1250         BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
1251         BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
1252         BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
1253         BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
1254         BUG_ON(pkt->bio->bi_private != pkt);
1255
1256         drop_super(sb);
1257         return 1;
1258
1259 out:
1260         drop_super(sb);
1261         return 0;
1262 #endif
1263 }
1264
1265 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1266 {
1267 #if PACKET_DEBUG > 1
1268         static const char *state_name[] = {
1269                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1270         };
1271         enum packet_data_state old_state = pkt->state;
1272         VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
1273                 state_name[old_state], state_name[state]);
1274 #endif
1275         pkt->state = state;
1276 }
1277
1278 /*
1279  * Scan the work queue to see if we can start a new packet.
1280  * returns non-zero if any work was done.
1281  */
1282 static int pkt_handle_queue(struct pktcdvd_device *pd)
1283 {
1284         struct packet_data *pkt, *p;
1285         struct bio *bio = NULL;
1286         sector_t zone = 0; /* Suppress gcc warning */
1287         struct pkt_rb_node *node, *first_node;
1288         struct rb_node *n;
1289         int wakeup;
1290
1291         VPRINTK("handle_queue\n");
1292
1293         atomic_set(&pd->scan_queue, 0);
1294
1295         if (list_empty(&pd->cdrw.pkt_free_list)) {
1296                 VPRINTK("handle_queue: no pkt\n");
1297                 return 0;
1298         }
1299
1300         /*
1301          * Try to find a zone we are not already working on.
1302          */
1303         spin_lock(&pd->lock);
1304         first_node = pkt_rbtree_find(pd, pd->current_sector);
1305         if (!first_node) {
1306                 n = rb_first(&pd->bio_queue);
1307                 if (n)
1308                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1309         }
1310         node = first_node;
1311         while (node) {
1312                 bio = node->bio;
1313                 zone = ZONE(bio->bi_sector, pd);
1314                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1315                         if (p->sector == zone) {
1316                                 bio = NULL;
1317                                 goto try_next_bio;
1318                         }
1319                 }
1320                 break;
1321 try_next_bio:
1322                 node = pkt_rbtree_next(node);
1323                 if (!node) {
1324                         n = rb_first(&pd->bio_queue);
1325                         if (n)
1326                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1327                 }
1328                 if (node == first_node)
1329                         node = NULL;
1330         }
1331         spin_unlock(&pd->lock);
1332         if (!bio) {
1333                 VPRINTK("handle_queue: no bio\n");
1334                 return 0;
1335         }
1336
1337         pkt = pkt_get_packet_data(pd, zone);
1338
1339         pd->current_sector = zone + pd->settings.size;
1340         pkt->sector = zone;
1341         BUG_ON(pkt->frames != pd->settings.size >> 2);
1342         pkt->write_size = 0;
1343
1344         /*
1345          * Scan work queue for bios in the same zone and link them
1346          * to this packet.
1347          */
1348         spin_lock(&pd->lock);
1349         VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
1350         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1351                 bio = node->bio;
1352                 VPRINTK("pkt_handle_queue: found zone=%llx\n",
1353                         (unsigned long long)ZONE(bio->bi_sector, pd));
1354                 if (ZONE(bio->bi_sector, pd) != zone)
1355                         break;
1356                 pkt_rbtree_erase(pd, node);
1357                 spin_lock(&pkt->lock);
1358                 pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
1359                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
1360                 spin_unlock(&pkt->lock);
1361         }
1362         /* check write congestion marks, and if bio_queue_size is
1363            below, wake up any waiters */
1364         wakeup = (pd->write_congestion_on > 0
1365                         && pd->bio_queue_size <= pd->write_congestion_off);
1366         spin_unlock(&pd->lock);
1367         if (wakeup)
1368                 clear_bdi_congested(&pd->disk->queue->backing_dev_info, WRITE);
1369
1370         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1371         pkt_set_state(pkt, PACKET_WAITING_STATE);
1372         atomic_set(&pkt->run_sm, 1);
1373
1374         spin_lock(&pd->cdrw.active_list_lock);
1375         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1376         spin_unlock(&pd->cdrw.active_list_lock);
1377
1378         return 1;
1379 }
1380
1381 /*
1382  * Assemble a bio to write one packet and queue the bio for processing
1383  * by the underlying block device.
1384  */
1385 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1386 {
1387         struct bio *bio;
1388         int f;
1389         int frames_write;
1390         struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1391
1392         for (f = 0; f < pkt->frames; f++) {
1393                 bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1394                 bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1395         }
1396
1397         /*
1398          * Fill-in bvec with data from orig_bios.
1399          */
1400         frames_write = 0;
1401         spin_lock(&pkt->lock);
1402         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1403                 int segment = bio->bi_idx;
1404                 int src_offs = 0;
1405                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1406                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1407                 BUG_ON(first_frame < 0);
1408                 BUG_ON(first_frame + num_frames > pkt->frames);
1409                 for (f = first_frame; f < first_frame + num_frames; f++) {
1410                         struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
1411
1412                         while (src_offs >= src_bvl->bv_len) {
1413                                 src_offs -= src_bvl->bv_len;
1414                                 segment++;
1415                                 BUG_ON(segment >= bio->bi_vcnt);
1416                                 src_bvl = bio_iovec_idx(bio, segment);
1417                         }
1418
1419                         if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
1420                                 bvec[f].bv_page = src_bvl->bv_page;
1421                                 bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
1422                         } else {
1423                                 pkt_copy_bio_data(bio, segment, src_offs,
1424                                                   bvec[f].bv_page, bvec[f].bv_offset);
1425                         }
1426                         src_offs += CD_FRAMESIZE;
1427                         frames_write++;
1428                 }
1429         }
1430         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1431         spin_unlock(&pkt->lock);
1432
1433         VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
1434                 frames_write, (unsigned long long)pkt->sector);
1435         BUG_ON(frames_write != pkt->write_size);
1436
1437         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1438                 pkt_make_local_copy(pkt, bvec);
1439                 pkt->cache_valid = 1;
1440         } else {
1441                 pkt->cache_valid = 0;
1442         }
1443
1444         /* Start the write request */
1445         bio_init(pkt->w_bio);
1446         pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
1447         pkt->w_bio->bi_sector = pkt->sector;
1448         pkt->w_bio->bi_bdev = pd->bdev;
1449         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1450         pkt->w_bio->bi_private = pkt;
1451         for (f = 0; f < pkt->frames; f++)
1452                 if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1453                         BUG();
1454         VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
1455
1456         atomic_set(&pkt->io_wait, 1);
1457         pkt->w_bio->bi_rw = WRITE;
1458         pkt_queue_bio(pd, pkt->w_bio);
1459 }
1460
1461 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1462 {
1463         struct bio *bio, *next;
1464
1465         if (!uptodate)
1466                 pkt->cache_valid = 0;
1467
1468         /* Finish all bios corresponding to this packet */
1469         bio = pkt->orig_bios;
1470         while (bio) {
1471                 next = bio->bi_next;
1472                 bio->bi_next = NULL;
1473                 bio_endio(bio, bio->bi_size, uptodate ? 0 : -EIO);
1474                 bio = next;
1475         }
1476         pkt->orig_bios = pkt->orig_bios_tail = NULL;
1477 }
1478
1479 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1480 {
1481         int uptodate;
1482
1483         VPRINTK("run_state_machine: pkt %d\n", pkt->id);
1484
1485         for (;;) {
1486                 switch (pkt->state) {
1487                 case PACKET_WAITING_STATE:
1488                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1489                                 return;
1490
1491                         pkt->sleep_time = 0;
1492                         pkt_gather_data(pd, pkt);
1493                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1494                         break;
1495
1496                 case PACKET_READ_WAIT_STATE:
1497                         if (atomic_read(&pkt->io_wait) > 0)
1498                                 return;
1499
1500                         if (atomic_read(&pkt->io_errors) > 0) {
1501                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1502                         } else {
1503                                 pkt_start_write(pd, pkt);
1504                         }
1505                         break;
1506
1507                 case PACKET_WRITE_WAIT_STATE:
1508                         if (atomic_read(&pkt->io_wait) > 0)
1509                                 return;
1510
1511                         if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1512                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1513                         } else {
1514                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1515                         }
1516                         break;
1517
1518                 case PACKET_RECOVERY_STATE:
1519                         if (pkt_start_recovery(pkt)) {
1520                                 pkt_start_write(pd, pkt);
1521                         } else {
1522                                 VPRINTK("No recovery possible\n");
1523                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1524                         }
1525                         break;
1526
1527                 case PACKET_FINISHED_STATE:
1528                         uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1529                         pkt_finish_packet(pkt, uptodate);
1530                         return;
1531
1532                 default:
1533                         BUG();
1534                         break;
1535                 }
1536         }
1537 }
1538
1539 static void pkt_handle_packets(struct pktcdvd_device *pd)
1540 {
1541         struct packet_data *pkt, *next;
1542
1543         VPRINTK("pkt_handle_packets\n");
1544
1545         /*
1546          * Run state machine for active packets
1547          */
1548         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1549                 if (atomic_read(&pkt->run_sm) > 0) {
1550                         atomic_set(&pkt->run_sm, 0);
1551                         pkt_run_state_machine(pd, pkt);
1552                 }
1553         }
1554
1555         /*
1556          * Move no longer active packets to the free list
1557          */
1558         spin_lock(&pd->cdrw.active_list_lock);
1559         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1560                 if (pkt->state == PACKET_FINISHED_STATE) {
1561                         list_del(&pkt->list);
1562                         pkt_put_packet_data(pd, pkt);
1563                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1564                         atomic_set(&pd->scan_queue, 1);
1565                 }
1566         }
1567         spin_unlock(&pd->cdrw.active_list_lock);
1568 }
1569
1570 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1571 {
1572         struct packet_data *pkt;
1573         int i;
1574
1575         for (i = 0; i < PACKET_NUM_STATES; i++)
1576                 states[i] = 0;
1577
1578         spin_lock(&pd->cdrw.active_list_lock);
1579         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1580                 states[pkt->state]++;
1581         }
1582         spin_unlock(&pd->cdrw.active_list_lock);
1583 }
1584
1585 /*
1586  * kcdrwd is woken up when writes have been queued for one of our
1587  * registered devices
1588  */
1589 static int kcdrwd(void *foobar)
1590 {
1591         struct pktcdvd_device *pd = foobar;
1592         struct packet_data *pkt;
1593         long min_sleep_time, residue;
1594
1595         set_user_nice(current, -20);
1596         set_freezable();
1597
1598         for (;;) {
1599                 DECLARE_WAITQUEUE(wait, current);
1600
1601                 /*
1602                  * Wait until there is something to do
1603                  */
1604                 add_wait_queue(&pd->wqueue, &wait);
1605                 for (;;) {
1606                         set_current_state(TASK_INTERRUPTIBLE);
1607
1608                         /* Check if we need to run pkt_handle_queue */
1609                         if (atomic_read(&pd->scan_queue) > 0)
1610                                 goto work_to_do;
1611
1612                         /* Check if we need to run the state machine for some packet */
1613                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1614                                 if (atomic_read(&pkt->run_sm) > 0)
1615                                         goto work_to_do;
1616                         }
1617
1618                         /* Check if we need to process the iosched queues */
1619                         if (atomic_read(&pd->iosched.attention) != 0)
1620                                 goto work_to_do;
1621
1622                         /* Otherwise, go to sleep */
1623                         if (PACKET_DEBUG > 1) {
1624                                 int states[PACKET_NUM_STATES];
1625                                 pkt_count_states(pd, states);
1626                                 VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1627                                         states[0], states[1], states[2], states[3],
1628                                         states[4], states[5]);
1629                         }
1630
1631                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1632                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1633                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1634                                         min_sleep_time = pkt->sleep_time;
1635                         }
1636
1637                         generic_unplug_device(bdev_get_queue(pd->bdev));
1638
1639                         VPRINTK("kcdrwd: sleeping\n");
1640                         residue = schedule_timeout(min_sleep_time);
1641                         VPRINTK("kcdrwd: wake up\n");
1642
1643                         /* make swsusp happy with our thread */
1644                         try_to_freeze();
1645
1646                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1647                                 if (!pkt->sleep_time)
1648                                         continue;
1649                                 pkt->sleep_time -= min_sleep_time - residue;
1650                                 if (pkt->sleep_time <= 0) {
1651                                         pkt->sleep_time = 0;
1652                                         atomic_inc(&pkt->run_sm);
1653                                 }
1654                         }
1655
1656                         if (kthread_should_stop())
1657                                 break;
1658                 }
1659 work_to_do:
1660                 set_current_state(TASK_RUNNING);
1661                 remove_wait_queue(&pd->wqueue, &wait);
1662
1663                 if (kthread_should_stop())
1664                         break;
1665
1666                 /*
1667                  * if pkt_handle_queue returns true, we can queue
1668                  * another request.
1669                  */
1670                 while (pkt_handle_queue(pd))
1671                         ;
1672
1673                 /*
1674                  * Handle packet state machine
1675                  */
1676                 pkt_handle_packets(pd);
1677
1678                 /*
1679                  * Handle iosched queues
1680                  */
1681                 pkt_iosched_process_queue(pd);
1682         }
1683
1684         return 0;
1685 }
1686
1687 static void pkt_print_settings(struct pktcdvd_device *pd)
1688 {
1689         printk(DRIVER_NAME": %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
1690         printk("%u blocks, ", pd->settings.size >> 2);
1691         printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
1692 }
1693
1694 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1695 {
1696         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1697
1698         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1699         cgc->cmd[2] = page_code | (page_control << 6);
1700         cgc->cmd[7] = cgc->buflen >> 8;
1701         cgc->cmd[8] = cgc->buflen & 0xff;
1702         cgc->data_direction = CGC_DATA_READ;
1703         return pkt_generic_packet(pd, cgc);
1704 }
1705
1706 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1707 {
1708         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1709         memset(cgc->buffer, 0, 2);
1710         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1711         cgc->cmd[1] = 0x10;             /* PF */
1712         cgc->cmd[7] = cgc->buflen >> 8;
1713         cgc->cmd[8] = cgc->buflen & 0xff;
1714         cgc->data_direction = CGC_DATA_WRITE;
1715         return pkt_generic_packet(pd, cgc);
1716 }
1717
1718 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1719 {
1720         struct packet_command cgc;
1721         int ret;
1722
1723         /* set up command and get the disc info */
1724         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1725         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1726         cgc.cmd[8] = cgc.buflen = 2;
1727         cgc.quiet = 1;
1728
1729         if ((ret = pkt_generic_packet(pd, &cgc)))
1730                 return ret;
1731
1732         /* not all drives have the same disc_info length, so requeue
1733          * packet with the length the drive tells us it can supply
1734          */
1735         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1736                      sizeof(di->disc_information_length);
1737
1738         if (cgc.buflen > sizeof(disc_information))
1739                 cgc.buflen = sizeof(disc_information);
1740
1741         cgc.cmd[8] = cgc.buflen;
1742         return pkt_generic_packet(pd, &cgc);
1743 }
1744
1745 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1746 {
1747         struct packet_command cgc;
1748         int ret;
1749
1750         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1751         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1752         cgc.cmd[1] = type & 3;
1753         cgc.cmd[4] = (track & 0xff00) >> 8;
1754         cgc.cmd[5] = track & 0xff;
1755         cgc.cmd[8] = 8;
1756         cgc.quiet = 1;
1757
1758         if ((ret = pkt_generic_packet(pd, &cgc)))
1759                 return ret;
1760
1761         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1762                      sizeof(ti->track_information_length);
1763
1764         if (cgc.buflen > sizeof(track_information))
1765                 cgc.buflen = sizeof(track_information);
1766
1767         cgc.cmd[8] = cgc.buflen;
1768         return pkt_generic_packet(pd, &cgc);
1769 }
1770
1771 static int pkt_get_last_written(struct pktcdvd_device *pd, long *last_written)
1772 {
1773         disc_information di;
1774         track_information ti;
1775         __u32 last_track;
1776         int ret = -1;
1777
1778         if ((ret = pkt_get_disc_info(pd, &di)))
1779                 return ret;
1780
1781         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1782         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1783                 return ret;
1784
1785         /* if this track is blank, try the previous. */
1786         if (ti.blank) {
1787                 last_track--;
1788                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1789                         return ret;
1790         }
1791
1792         /* if last recorded field is valid, return it. */
1793         if (ti.lra_v) {
1794                 *last_written = be32_to_cpu(ti.last_rec_address);
1795         } else {
1796                 /* make it up instead */
1797                 *last_written = be32_to_cpu(ti.track_start) +
1798                                 be32_to_cpu(ti.track_size);
1799                 if (ti.free_blocks)
1800                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1801         }
1802         return 0;
1803 }
1804
1805 /*
1806  * write mode select package based on pd->settings
1807  */
1808 static int pkt_set_write_settings(struct pktcdvd_device *pd)
1809 {
1810         struct packet_command cgc;
1811         struct request_sense sense;
1812         write_param_page *wp;
1813         char buffer[128];
1814         int ret, size;
1815
1816         /* doesn't apply to DVD+RW or DVD-RAM */
1817         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1818                 return 0;
1819
1820         memset(buffer, 0, sizeof(buffer));
1821         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1822         cgc.sense = &sense;
1823         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1824                 pkt_dump_sense(&cgc);
1825                 return ret;
1826         }
1827
1828         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1829         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1830         if (size > sizeof(buffer))
1831                 size = sizeof(buffer);
1832
1833         /*
1834          * now get it all
1835          */
1836         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1837         cgc.sense = &sense;
1838         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1839                 pkt_dump_sense(&cgc);
1840                 return ret;
1841         }
1842
1843         /*
1844          * write page is offset header + block descriptor length
1845          */
1846         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1847
1848         wp->fp = pd->settings.fp;
1849         wp->track_mode = pd->settings.track_mode;
1850         wp->write_type = pd->settings.write_type;
1851         wp->data_block_type = pd->settings.block_mode;
1852
1853         wp->multi_session = 0;
1854
1855 #ifdef PACKET_USE_LS
1856         wp->link_size = 7;
1857         wp->ls_v = 1;
1858 #endif
1859
1860         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1861                 wp->session_format = 0;
1862                 wp->subhdr2 = 0x20;
1863         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1864                 wp->session_format = 0x20;
1865                 wp->subhdr2 = 8;
1866 #if 0
1867                 wp->mcn[0] = 0x80;
1868                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1869 #endif
1870         } else {
1871                 /*
1872                  * paranoia
1873                  */
1874                 printk(DRIVER_NAME": write mode wrong %d\n", wp->data_block_type);
1875                 return 1;
1876         }
1877         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1878
1879         cgc.buflen = cgc.cmd[8] = size;
1880         if ((ret = pkt_mode_select(pd, &cgc))) {
1881                 pkt_dump_sense(&cgc);
1882                 return ret;
1883         }
1884
1885         pkt_print_settings(pd);
1886         return 0;
1887 }
1888
1889 /*
1890  * 1 -- we can write to this track, 0 -- we can't
1891  */
1892 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1893 {
1894         switch (pd->mmc3_profile) {
1895                 case 0x1a: /* DVD+RW */
1896                 case 0x12: /* DVD-RAM */
1897                         /* The track is always writable on DVD+RW/DVD-RAM */
1898                         return 1;
1899                 default:
1900                         break;
1901         }
1902
1903         if (!ti->packet || !ti->fp)
1904                 return 0;
1905
1906         /*
1907          * "good" settings as per Mt Fuji.
1908          */
1909         if (ti->rt == 0 && ti->blank == 0)
1910                 return 1;
1911
1912         if (ti->rt == 0 && ti->blank == 1)
1913                 return 1;
1914
1915         if (ti->rt == 1 && ti->blank == 0)
1916                 return 1;
1917
1918         printk(DRIVER_NAME": bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1919         return 0;
1920 }
1921
1922 /*
1923  * 1 -- we can write to this disc, 0 -- we can't
1924  */
1925 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1926 {
1927         switch (pd->mmc3_profile) {
1928                 case 0x0a: /* CD-RW */
1929                 case 0xffff: /* MMC3 not supported */
1930                         break;
1931                 case 0x1a: /* DVD+RW */
1932                 case 0x13: /* DVD-RW */
1933                 case 0x12: /* DVD-RAM */
1934                         return 1;
1935                 default:
1936                         VPRINTK(DRIVER_NAME": Wrong disc profile (%x)\n", pd->mmc3_profile);
1937                         return 0;
1938         }
1939
1940         /*
1941          * for disc type 0xff we should probably reserve a new track.
1942          * but i'm not sure, should we leave this to user apps? probably.
1943          */
1944         if (di->disc_type == 0xff) {
1945                 printk(DRIVER_NAME": Unknown disc. No track?\n");
1946                 return 0;
1947         }
1948
1949         if (di->disc_type != 0x20 && di->disc_type != 0) {
1950                 printk(DRIVER_NAME": Wrong disc type (%x)\n", di->disc_type);
1951                 return 0;
1952         }
1953
1954         if (di->erasable == 0) {
1955                 printk(DRIVER_NAME": Disc not erasable\n");
1956                 return 0;
1957         }
1958
1959         if (di->border_status == PACKET_SESSION_RESERVED) {
1960                 printk(DRIVER_NAME": Can't write to last track (reserved)\n");
1961                 return 0;
1962         }
1963
1964         return 1;
1965 }
1966
1967 static int pkt_probe_settings(struct pktcdvd_device *pd)
1968 {
1969         struct packet_command cgc;
1970         unsigned char buf[12];
1971         disc_information di;
1972         track_information ti;
1973         int ret, track;
1974
1975         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1976         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1977         cgc.cmd[8] = 8;
1978         ret = pkt_generic_packet(pd, &cgc);
1979         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1980
1981         memset(&di, 0, sizeof(disc_information));
1982         memset(&ti, 0, sizeof(track_information));
1983
1984         if ((ret = pkt_get_disc_info(pd, &di))) {
1985                 printk("failed get_disc\n");
1986                 return ret;
1987         }
1988
1989         if (!pkt_writable_disc(pd, &di))
1990                 return -EROFS;
1991
1992         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1993
1994         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1995         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1996                 printk(DRIVER_NAME": failed get_track\n");
1997                 return ret;
1998         }
1999
2000         if (!pkt_writable_track(pd, &ti)) {
2001                 printk(DRIVER_NAME": can't write to this track\n");
2002                 return -EROFS;
2003         }
2004
2005         /*
2006          * we keep packet size in 512 byte units, makes it easier to
2007          * deal with request calculations.
2008          */
2009         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
2010         if (pd->settings.size == 0) {
2011                 printk(DRIVER_NAME": detected zero packet size!\n");
2012                 return -ENXIO;
2013         }
2014         if (pd->settings.size > PACKET_MAX_SECTORS) {
2015                 printk(DRIVER_NAME": packet size is too big\n");
2016                 return -EROFS;
2017         }
2018         pd->settings.fp = ti.fp;
2019         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
2020
2021         if (ti.nwa_v) {
2022                 pd->nwa = be32_to_cpu(ti.next_writable);
2023                 set_bit(PACKET_NWA_VALID, &pd->flags);
2024         }
2025
2026         /*
2027          * in theory we could use lra on -RW media as well and just zero
2028          * blocks that haven't been written yet, but in practice that
2029          * is just a no-go. we'll use that for -R, naturally.
2030          */
2031         if (ti.lra_v) {
2032                 pd->lra = be32_to_cpu(ti.last_rec_address);
2033                 set_bit(PACKET_LRA_VALID, &pd->flags);
2034         } else {
2035                 pd->lra = 0xffffffff;
2036                 set_bit(PACKET_LRA_VALID, &pd->flags);
2037         }
2038
2039         /*
2040          * fine for now
2041          */
2042         pd->settings.link_loss = 7;
2043         pd->settings.write_type = 0;    /* packet */
2044         pd->settings.track_mode = ti.track_mode;
2045
2046         /*
2047          * mode1 or mode2 disc
2048          */
2049         switch (ti.data_mode) {
2050                 case PACKET_MODE1:
2051                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
2052                         break;
2053                 case PACKET_MODE2:
2054                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
2055                         break;
2056                 default:
2057                         printk(DRIVER_NAME": unknown data mode\n");
2058                         return -EROFS;
2059         }
2060         return 0;
2061 }
2062
2063 /*
2064  * enable/disable write caching on drive
2065  */
2066 static int pkt_write_caching(struct pktcdvd_device *pd, int set)
2067 {
2068         struct packet_command cgc;
2069         struct request_sense sense;
2070         unsigned char buf[64];
2071         int ret;
2072
2073         memset(buf, 0, sizeof(buf));
2074         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
2075         cgc.sense = &sense;
2076         cgc.buflen = pd->mode_offset + 12;
2077
2078         /*
2079          * caching mode page might not be there, so quiet this command
2080          */
2081         cgc.quiet = 1;
2082
2083         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
2084                 return ret;
2085
2086         buf[pd->mode_offset + 10] |= (!!set << 2);
2087
2088         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
2089         ret = pkt_mode_select(pd, &cgc);
2090         if (ret) {
2091                 printk(DRIVER_NAME": write caching control failed\n");
2092                 pkt_dump_sense(&cgc);
2093         } else if (!ret && set)
2094                 printk(DRIVER_NAME": enabled write caching on %s\n", pd->name);
2095         return ret;
2096 }
2097
2098 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
2099 {
2100         struct packet_command cgc;
2101
2102         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2103         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
2104         cgc.cmd[4] = lockflag ? 1 : 0;
2105         return pkt_generic_packet(pd, &cgc);
2106 }
2107
2108 /*
2109  * Returns drive maximum write speed
2110  */
2111 static int pkt_get_max_speed(struct pktcdvd_device *pd, unsigned *write_speed)
2112 {
2113         struct packet_command cgc;
2114         struct request_sense sense;
2115         unsigned char buf[256+18];
2116         unsigned char *cap_buf;
2117         int ret, offset;
2118
2119         memset(buf, 0, sizeof(buf));
2120         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
2121         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
2122         cgc.sense = &sense;
2123
2124         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2125         if (ret) {
2126                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2127                              sizeof(struct mode_page_header);
2128                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2129                 if (ret) {
2130                         pkt_dump_sense(&cgc);
2131                         return ret;
2132                 }
2133         }
2134
2135         offset = 20;                        /* Obsoleted field, used by older drives */
2136         if (cap_buf[1] >= 28)
2137                 offset = 28;                /* Current write speed selected */
2138         if (cap_buf[1] >= 30) {
2139                 /* If the drive reports at least one "Logical Unit Write
2140                  * Speed Performance Descriptor Block", use the information
2141                  * in the first block. (contains the highest speed)
2142                  */
2143                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2144                 if (num_spdb > 0)
2145                         offset = 34;
2146         }
2147
2148         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2149         return 0;
2150 }
2151
2152 /* These tables from cdrecord - I don't have orange book */
2153 /* standard speed CD-RW (1-4x) */
2154 static char clv_to_speed[16] = {
2155         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2156            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2157 };
2158 /* high speed CD-RW (-10x) */
2159 static char hs_clv_to_speed[16] = {
2160         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2161            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2162 };
2163 /* ultra high speed CD-RW */
2164 static char us_clv_to_speed[16] = {
2165         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2166            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2167 };
2168
2169 /*
2170  * reads the maximum media speed from ATIP
2171  */
2172 static int pkt_media_speed(struct pktcdvd_device *pd, unsigned *speed)
2173 {
2174         struct packet_command cgc;
2175         struct request_sense sense;
2176         unsigned char buf[64];
2177         unsigned int size, st, sp;
2178         int ret;
2179
2180         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2181         cgc.sense = &sense;
2182         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2183         cgc.cmd[1] = 2;
2184         cgc.cmd[2] = 4; /* READ ATIP */
2185         cgc.cmd[8] = 2;
2186         ret = pkt_generic_packet(pd, &cgc);
2187         if (ret) {
2188                 pkt_dump_sense(&cgc);
2189                 return ret;
2190         }
2191         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2192         if (size > sizeof(buf))
2193                 size = sizeof(buf);
2194
2195         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2196         cgc.sense = &sense;
2197         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2198         cgc.cmd[1] = 2;
2199         cgc.cmd[2] = 4;
2200         cgc.cmd[8] = size;
2201         ret = pkt_generic_packet(pd, &cgc);
2202         if (ret) {
2203                 pkt_dump_sense(&cgc);
2204                 return ret;
2205         }
2206
2207         if (!buf[6] & 0x40) {
2208                 printk(DRIVER_NAME": Disc type is not CD-RW\n");
2209                 return 1;
2210         }
2211         if (!buf[6] & 0x4) {
2212                 printk(DRIVER_NAME": A1 values on media are not valid, maybe not CDRW?\n");
2213                 return 1;
2214         }
2215
2216         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2217
2218         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2219
2220         /* Info from cdrecord */
2221         switch (st) {
2222                 case 0: /* standard speed */
2223                         *speed = clv_to_speed[sp];
2224                         break;
2225                 case 1: /* high speed */
2226                         *speed = hs_clv_to_speed[sp];
2227                         break;
2228                 case 2: /* ultra high speed */
2229                         *speed = us_clv_to_speed[sp];
2230                         break;
2231                 default:
2232                         printk(DRIVER_NAME": Unknown disc sub-type %d\n",st);
2233                         return 1;
2234         }
2235         if (*speed) {
2236                 printk(DRIVER_NAME": Max. media speed: %d\n",*speed);
2237                 return 0;
2238         } else {
2239                 printk(DRIVER_NAME": Unknown speed %d for sub-type %d\n",sp,st);
2240                 return 1;
2241         }
2242 }
2243
2244 static int pkt_perform_opc(struct pktcdvd_device *pd)
2245 {
2246         struct packet_command cgc;
2247         struct request_sense sense;
2248         int ret;
2249
2250         VPRINTK(DRIVER_NAME": Performing OPC\n");
2251
2252         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2253         cgc.sense = &sense;
2254         cgc.timeout = 60*HZ;
2255         cgc.cmd[0] = GPCMD_SEND_OPC;
2256         cgc.cmd[1] = 1;
2257         if ((ret = pkt_generic_packet(pd, &cgc)))
2258                 pkt_dump_sense(&cgc);
2259         return ret;
2260 }
2261
2262 static int pkt_open_write(struct pktcdvd_device *pd)
2263 {
2264         int ret;
2265         unsigned int write_speed, media_write_speed, read_speed;
2266
2267         if ((ret = pkt_probe_settings(pd))) {
2268                 VPRINTK(DRIVER_NAME": %s failed probe\n", pd->name);
2269                 return ret;
2270         }
2271
2272         if ((ret = pkt_set_write_settings(pd))) {
2273                 DPRINTK(DRIVER_NAME": %s failed saving write settings\n", pd->name);
2274                 return -EIO;
2275         }
2276
2277         pkt_write_caching(pd, USE_WCACHING);
2278
2279         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2280                 write_speed = 16 * 177;
2281         switch (pd->mmc3_profile) {
2282                 case 0x13: /* DVD-RW */
2283                 case 0x1a: /* DVD+RW */
2284                 case 0x12: /* DVD-RAM */
2285                         DPRINTK(DRIVER_NAME": write speed %ukB/s\n", write_speed);
2286                         break;
2287                 default:
2288                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2289                                 media_write_speed = 16;
2290                         write_speed = min(write_speed, media_write_speed * 177);
2291                         DPRINTK(DRIVER_NAME": write speed %ux\n", write_speed / 176);
2292                         break;
2293         }
2294         read_speed = write_speed;
2295
2296         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2297                 DPRINTK(DRIVER_NAME": %s couldn't set write speed\n", pd->name);
2298                 return -EIO;
2299         }
2300         pd->write_speed = write_speed;
2301         pd->read_speed = read_speed;
2302
2303         if ((ret = pkt_perform_opc(pd))) {
2304                 DPRINTK(DRIVER_NAME": %s Optimum Power Calibration failed\n", pd->name);
2305         }
2306
2307         return 0;
2308 }
2309
2310 /*
2311  * called at open time.
2312  */
2313 static int pkt_open_dev(struct pktcdvd_device *pd, int write)
2314 {
2315         int ret;
2316         long lba;
2317         struct request_queue *q;
2318
2319         /*
2320          * We need to re-open the cdrom device without O_NONBLOCK to be able
2321          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2322          * so bdget() can't fail.
2323          */
2324         bdget(pd->bdev->bd_dev);
2325         if ((ret = blkdev_get(pd->bdev, FMODE_READ, O_RDONLY)))
2326                 goto out;
2327
2328         if ((ret = bd_claim(pd->bdev, pd)))
2329                 goto out_putdev;
2330
2331         if ((ret = pkt_get_last_written(pd, &lba))) {
2332                 printk(DRIVER_NAME": pkt_get_last_written failed\n");
2333                 goto out_unclaim;
2334         }
2335
2336         set_capacity(pd->disk, lba << 2);
2337         set_capacity(pd->bdev->bd_disk, lba << 2);
2338         bd_set_size(pd->bdev, (loff_t)lba << 11);
2339
2340         q = bdev_get_queue(pd->bdev);
2341         if (write) {
2342                 if ((ret = pkt_open_write(pd)))
2343                         goto out_unclaim;
2344                 /*
2345                  * Some CDRW drives can not handle writes larger than one packet,
2346                  * even if the size is a multiple of the packet size.
2347                  */
2348                 spin_lock_irq(q->queue_lock);
2349                 blk_queue_max_sectors(q, pd->settings.size);
2350                 spin_unlock_irq(q->queue_lock);
2351                 set_bit(PACKET_WRITABLE, &pd->flags);
2352         } else {
2353                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2354                 clear_bit(PACKET_WRITABLE, &pd->flags);
2355         }
2356
2357         if ((ret = pkt_set_segment_merging(pd, q)))
2358                 goto out_unclaim;
2359
2360         if (write) {
2361                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2362                         printk(DRIVER_NAME": not enough memory for buffers\n");
2363                         ret = -ENOMEM;
2364                         goto out_unclaim;
2365                 }
2366                 printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
2367         }
2368
2369         return 0;
2370
2371 out_unclaim:
2372         bd_release(pd->bdev);
2373 out_putdev:
2374         blkdev_put(pd->bdev);
2375 out:
2376         return ret;
2377 }
2378
2379 /*
2380  * called when the device is closed. makes sure that the device flushes
2381  * the internal cache before we close.
2382  */
2383 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2384 {
2385         if (flush && pkt_flush_cache(pd))
2386                 DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
2387
2388         pkt_lock_door(pd, 0);
2389
2390         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2391         bd_release(pd->bdev);
2392         blkdev_put(pd->bdev);
2393
2394         pkt_shrink_pktlist(pd);
2395 }
2396
2397 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
2398 {
2399         if (dev_minor >= MAX_WRITERS)
2400                 return NULL;
2401         return pkt_devs[dev_minor];
2402 }
2403
2404 static int pkt_open(struct inode *inode, struct file *file)
2405 {
2406         struct pktcdvd_device *pd = NULL;
2407         int ret;
2408
2409         VPRINTK(DRIVER_NAME": entering open\n");
2410
2411         mutex_lock(&ctl_mutex);
2412         pd = pkt_find_dev_from_minor(iminor(inode));
2413         if (!pd) {
2414                 ret = -ENODEV;
2415                 goto out;
2416         }
2417         BUG_ON(pd->refcnt < 0);
2418
2419         pd->refcnt++;
2420         if (pd->refcnt > 1) {
2421                 if ((file->f_mode & FMODE_WRITE) &&
2422                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2423                         ret = -EBUSY;
2424                         goto out_dec;
2425                 }
2426         } else {
2427                 ret = pkt_open_dev(pd, file->f_mode & FMODE_WRITE);
2428                 if (ret)
2429                         goto out_dec;
2430                 /*
2431                  * needed here as well, since ext2 (among others) may change
2432                  * the blocksize at mount time
2433                  */
2434                 set_blocksize(inode->i_bdev, CD_FRAMESIZE);
2435         }
2436
2437         mutex_unlock(&ctl_mutex);
2438         return 0;
2439
2440 out_dec:
2441         pd->refcnt--;
2442 out:
2443         VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
2444         mutex_unlock(&ctl_mutex);
2445         return ret;
2446 }
2447
2448 static int pkt_close(struct inode *inode, struct file *file)
2449 {
2450         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2451         int ret = 0;
2452
2453         mutex_lock(&ctl_mutex);
2454         pd->refcnt--;
2455         BUG_ON(pd->refcnt < 0);
2456         if (pd->refcnt == 0) {
2457                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2458                 pkt_release_dev(pd, flush);
2459         }
2460         mutex_unlock(&ctl_mutex);
2461         return ret;
2462 }
2463
2464
2465 static int pkt_end_io_read_cloned(struct bio *bio, unsigned int bytes_done, int err)
2466 {
2467         struct packet_stacked_data *psd = bio->bi_private;
2468         struct pktcdvd_device *pd = psd->pd;
2469
2470         if (bio->bi_size)
2471                 return 1;
2472
2473         bio_put(bio);
2474         bio_endio(psd->bio, psd->bio->bi_size, err);
2475         mempool_free(psd, psd_pool);
2476         pkt_bio_finished(pd);
2477         return 0;
2478 }
2479
2480 static int pkt_make_request(struct request_queue *q, struct bio *bio)
2481 {
2482         struct pktcdvd_device *pd;
2483         char b[BDEVNAME_SIZE];
2484         sector_t zone;
2485         struct packet_data *pkt;
2486         int was_empty, blocked_bio;
2487         struct pkt_rb_node *node;
2488
2489         pd = q->queuedata;
2490         if (!pd) {
2491                 printk(DRIVER_NAME": %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
2492                 goto end_io;
2493         }
2494
2495         /*
2496          * Clone READ bios so we can have our own bi_end_io callback.
2497          */
2498         if (bio_data_dir(bio) == READ) {
2499                 struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2500                 struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2501
2502                 psd->pd = pd;
2503                 psd->bio = bio;
2504                 cloned_bio->bi_bdev = pd->bdev;
2505                 cloned_bio->bi_private = psd;
2506                 cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2507                 pd->stats.secs_r += bio->bi_size >> 9;
2508                 pkt_queue_bio(pd, cloned_bio);
2509                 return 0;
2510         }
2511
2512         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2513                 printk(DRIVER_NAME": WRITE for ro device %s (%llu)\n",
2514                         pd->name, (unsigned long long)bio->bi_sector);
2515                 goto end_io;
2516         }
2517
2518         if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
2519                 printk(DRIVER_NAME": wrong bio size\n");
2520                 goto end_io;
2521         }
2522
2523         blk_queue_bounce(q, &bio);
2524
2525         zone = ZONE(bio->bi_sector, pd);
2526         VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
2527                 (unsigned long long)bio->bi_sector,
2528                 (unsigned long long)(bio->bi_sector + bio_sectors(bio)));
2529
2530         /* Check if we have to split the bio */
2531         {
2532                 struct bio_pair *bp;
2533                 sector_t last_zone;
2534                 int first_sectors;
2535
2536                 last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
2537                 if (last_zone != zone) {
2538                         BUG_ON(last_zone != zone + pd->settings.size);
2539                         first_sectors = last_zone - bio->bi_sector;
2540                         bp = bio_split(bio, bio_split_pool, first_sectors);
2541                         BUG_ON(!bp);
2542                         pkt_make_request(q, &bp->bio1);
2543                         pkt_make_request(q, &bp->bio2);
2544                         bio_pair_release(bp);
2545                         return 0;
2546                 }
2547         }
2548
2549         /*
2550          * If we find a matching packet in state WAITING or READ_WAIT, we can
2551          * just append this bio to that packet.
2552          */
2553         spin_lock(&pd->cdrw.active_list_lock);
2554         blocked_bio = 0;
2555         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2556                 if (pkt->sector == zone) {
2557                         spin_lock(&pkt->lock);
2558                         if ((pkt->state == PACKET_WAITING_STATE) ||
2559                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2560                                 pkt_add_list_last(bio, &pkt->orig_bios,
2561                                                   &pkt->orig_bios_tail);
2562                                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
2563                                 if ((pkt->write_size >= pkt->frames) &&
2564                                     (pkt->state == PACKET_WAITING_STATE)) {
2565                                         atomic_inc(&pkt->run_sm);
2566                                         wake_up(&pd->wqueue);
2567                                 }
2568                                 spin_unlock(&pkt->lock);
2569                                 spin_unlock(&pd->cdrw.active_list_lock);
2570                                 return 0;
2571                         } else {
2572                                 blocked_bio = 1;
2573                         }
2574                         spin_unlock(&pkt->lock);
2575                 }
2576         }
2577         spin_unlock(&pd->cdrw.active_list_lock);
2578
2579         /*
2580          * Test if there is enough room left in the bio work queue
2581          * (queue size >= congestion on mark).
2582          * If not, wait till the work queue size is below the congestion off mark.
2583          */
2584         spin_lock(&pd->lock);
2585         if (pd->write_congestion_on > 0
2586             && pd->bio_queue_size >= pd->write_congestion_on) {
2587                 set_bdi_congested(&q->backing_dev_info, WRITE);
2588                 do {
2589                         spin_unlock(&pd->lock);
2590                         congestion_wait(WRITE, HZ);
2591                         spin_lock(&pd->lock);
2592                 } while(pd->bio_queue_size > pd->write_congestion_off);
2593         }
2594         spin_unlock(&pd->lock);
2595
2596         /*
2597          * No matching packet found. Store the bio in the work queue.
2598          */
2599         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2600         node->bio = bio;
2601         spin_lock(&pd->lock);
2602         BUG_ON(pd->bio_queue_size < 0);
2603         was_empty = (pd->bio_queue_size == 0);
2604         pkt_rbtree_insert(pd, node);
2605         spin_unlock(&pd->lock);
2606
2607         /*
2608          * Wake up the worker thread.
2609          */
2610         atomic_set(&pd->scan_queue, 1);
2611         if (was_empty) {
2612                 /* This wake_up is required for correct operation */
2613                 wake_up(&pd->wqueue);
2614         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2615                 /*
2616                  * This wake up is not required for correct operation,
2617                  * but improves performance in some cases.
2618                  */
2619                 wake_up(&pd->wqueue);
2620         }
2621         return 0;
2622 end_io:
2623         bio_io_error(bio, bio->bi_size);
2624         return 0;
2625 }
2626
2627
2628
2629 static int pkt_merge_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *bvec)
2630 {
2631         struct pktcdvd_device *pd = q->queuedata;
2632         sector_t zone = ZONE(bio->bi_sector, pd);
2633         int used = ((bio->bi_sector - zone) << 9) + bio->bi_size;
2634         int remaining = (pd->settings.size << 9) - used;
2635         int remaining2;
2636
2637         /*
2638          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2639          * boundary, pkt_make_request() will split the bio.
2640          */
2641         remaining2 = PAGE_SIZE - bio->bi_size;
2642         remaining = max(remaining, remaining2);
2643
2644         BUG_ON(remaining < 0);
2645         return remaining;
2646 }
2647
2648 static void pkt_init_queue(struct pktcdvd_device *pd)
2649 {
2650         struct request_queue *q = pd->disk->queue;
2651
2652         blk_queue_make_request(q, pkt_make_request);
2653         blk_queue_hardsect_size(q, CD_FRAMESIZE);
2654         blk_queue_max_sectors(q, PACKET_MAX_SECTORS);
2655         blk_queue_merge_bvec(q, pkt_merge_bvec);
2656         q->queuedata = pd;
2657 }
2658
2659 static int pkt_seq_show(struct seq_file *m, void *p)
2660 {
2661         struct pktcdvd_device *pd = m->private;
2662         char *msg;
2663         char bdev_buf[BDEVNAME_SIZE];
2664         int states[PACKET_NUM_STATES];
2665
2666         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2667                    bdevname(pd->bdev, bdev_buf));
2668
2669         seq_printf(m, "\nSettings:\n");
2670         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2671
2672         if (pd->settings.write_type == 0)
2673                 msg = "Packet";
2674         else
2675                 msg = "Unknown";
2676         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2677
2678         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2679         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2680
2681         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2682
2683         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2684                 msg = "Mode 1";
2685         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2686                 msg = "Mode 2";
2687         else
2688                 msg = "Unknown";
2689         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2690
2691         seq_printf(m, "\nStatistics:\n");
2692         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2693         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2694         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2695         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2696         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2697
2698         seq_printf(m, "\nMisc:\n");
2699         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2700         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2701         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2702         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2703         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2704         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2705
2706         seq_printf(m, "\nQueue state:\n");
2707         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2708         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2709         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2710
2711         pkt_count_states(pd, states);
2712         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2713                    states[0], states[1], states[2], states[3], states[4], states[5]);
2714
2715         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2716                         pd->write_congestion_off,
2717                         pd->write_congestion_on);
2718         return 0;
2719 }
2720
2721 static int pkt_seq_open(struct inode *inode, struct file *file)
2722 {
2723         return single_open(file, pkt_seq_show, PDE(inode)->data);
2724 }
2725
2726 static const struct file_operations pkt_proc_fops = {
2727         .open   = pkt_seq_open,
2728         .read   = seq_read,
2729         .llseek = seq_lseek,
2730         .release = single_release
2731 };
2732
2733 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2734 {
2735         int i;
2736         int ret = 0;
2737         char b[BDEVNAME_SIZE];
2738         struct proc_dir_entry *proc;
2739         struct block_device *bdev;
2740
2741         if (pd->pkt_dev == dev) {
2742                 printk(DRIVER_NAME": Recursive setup not allowed\n");
2743                 return -EBUSY;
2744         }
2745         for (i = 0; i < MAX_WRITERS; i++) {
2746                 struct pktcdvd_device *pd2 = pkt_devs[i];
2747                 if (!pd2)
2748                         continue;
2749                 if (pd2->bdev->bd_dev == dev) {
2750                         printk(DRIVER_NAME": %s already setup\n", bdevname(pd2->bdev, b));
2751                         return -EBUSY;
2752                 }
2753                 if (pd2->pkt_dev == dev) {
2754                         printk(DRIVER_NAME": Can't chain pktcdvd devices\n");
2755                         return -EBUSY;
2756                 }
2757         }
2758
2759         bdev = bdget(dev);
2760         if (!bdev)
2761                 return -ENOMEM;
2762         ret = blkdev_get(bdev, FMODE_READ, O_RDONLY | O_NONBLOCK);
2763         if (ret)
2764                 return ret;
2765
2766         /* This is safe, since we have a reference from open(). */
2767         __module_get(THIS_MODULE);
2768
2769         pd->bdev = bdev;
2770         set_blocksize(bdev, CD_FRAMESIZE);
2771
2772         pkt_init_queue(pd);
2773
2774         atomic_set(&pd->cdrw.pending_bios, 0);
2775         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2776         if (IS_ERR(pd->cdrw.thread)) {
2777                 printk(DRIVER_NAME": can't start kernel thread\n");
2778                 ret = -ENOMEM;
2779                 goto out_mem;
2780         }
2781
2782         proc = create_proc_entry(pd->name, 0, pkt_proc);
2783         if (proc) {
2784                 proc->data = pd;
2785                 proc->proc_fops = &pkt_proc_fops;
2786         }
2787         DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
2788         return 0;
2789
2790 out_mem:
2791         blkdev_put(bdev);
2792         /* This is safe: open() is still holding a reference. */
2793         module_put(THIS_MODULE);
2794         return ret;
2795 }
2796
2797 static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
2798 {
2799         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2800
2801         VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd, imajor(inode), iminor(inode));
2802
2803         switch (cmd) {
2804         /*
2805          * forward selected CDROM ioctls to CD-ROM, for UDF
2806          */
2807         case CDROMMULTISESSION:
2808         case CDROMREADTOCENTRY:
2809         case CDROM_LAST_WRITTEN:
2810         case CDROM_SEND_PACKET:
2811         case SCSI_IOCTL_SEND_COMMAND:
2812                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2813
2814         case CDROMEJECT:
2815                 /*
2816                  * The door gets locked when the device is opened, so we
2817                  * have to unlock it or else the eject command fails.
2818                  */
2819                 if (pd->refcnt == 1)
2820                         pkt_lock_door(pd, 0);
2821                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2822
2823         default:
2824                 VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, cmd);
2825                 return -ENOTTY;
2826         }
2827
2828         return 0;
2829 }
2830
2831 static int pkt_media_changed(struct gendisk *disk)
2832 {
2833         struct pktcdvd_device *pd = disk->private_data;
2834         struct gendisk *attached_disk;
2835
2836         if (!pd)
2837                 return 0;
2838         if (!pd->bdev)
2839                 return 0;
2840         attached_disk = pd->bdev->bd_disk;
2841         if (!attached_disk)
2842                 return 0;
2843         return attached_disk->fops->media_changed(attached_disk);
2844 }
2845
2846 static struct block_device_operations pktcdvd_ops = {
2847         .owner =                THIS_MODULE,
2848         .open =                 pkt_open,
2849         .release =              pkt_close,
2850         .ioctl =                pkt_ioctl,
2851         .media_changed =        pkt_media_changed,
2852 };
2853
2854 /*
2855  * Set up mapping from pktcdvd device to CD-ROM device.
2856  */
2857 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2858 {
2859         int idx;
2860         int ret = -ENOMEM;
2861         struct pktcdvd_device *pd;
2862         struct gendisk *disk;
2863
2864         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2865
2866         for (idx = 0; idx < MAX_WRITERS; idx++)
2867                 if (!pkt_devs[idx])
2868                         break;
2869         if (idx == MAX_WRITERS) {
2870                 printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
2871                 ret = -EBUSY;
2872                 goto out_mutex;
2873         }
2874
2875         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2876         if (!pd)
2877                 goto out_mutex;
2878
2879         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2880                                                   sizeof(struct pkt_rb_node));
2881         if (!pd->rb_pool)
2882                 goto out_mem;
2883
2884         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2885         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2886         spin_lock_init(&pd->cdrw.active_list_lock);
2887
2888         spin_lock_init(&pd->lock);
2889         spin_lock_init(&pd->iosched.lock);
2890         sprintf(pd->name, DRIVER_NAME"%d", idx);
2891         init_waitqueue_head(&pd->wqueue);
2892         pd->bio_queue = RB_ROOT;
2893
2894         pd->write_congestion_on  = write_congestion_on;
2895         pd->write_congestion_off = write_congestion_off;
2896
2897         disk = alloc_disk(1);
2898         if (!disk)
2899                 goto out_mem;
2900         pd->disk = disk;
2901         disk->major = pktdev_major;
2902         disk->first_minor = idx;
2903         disk->fops = &pktcdvd_ops;
2904         disk->flags = GENHD_FL_REMOVABLE;
2905         strcpy(disk->disk_name, pd->name);
2906         disk->private_data = pd;
2907         disk->queue = blk_alloc_queue(GFP_KERNEL);
2908         if (!disk->queue)
2909                 goto out_mem2;
2910
2911         pd->pkt_dev = MKDEV(disk->major, disk->first_minor);
2912         ret = pkt_new_dev(pd, dev);
2913         if (ret)
2914                 goto out_new_dev;
2915
2916         add_disk(disk);
2917
2918         pkt_sysfs_dev_new(pd);
2919         pkt_debugfs_dev_new(pd);
2920
2921         pkt_devs[idx] = pd;
2922         if (pkt_dev)
2923                 *pkt_dev = pd->pkt_dev;
2924
2925         mutex_unlock(&ctl_mutex);
2926         return 0;
2927
2928 out_new_dev:
2929         blk_cleanup_queue(disk->queue);
2930 out_mem2:
2931         put_disk(disk);
2932 out_mem:
2933         if (pd->rb_pool)
2934                 mempool_destroy(pd->rb_pool);
2935         kfree(pd);
2936 out_mutex:
2937         mutex_unlock(&ctl_mutex);
2938         printk(DRIVER_NAME": setup of pktcdvd device failed\n");
2939         return ret;
2940 }
2941
2942 /*
2943  * Tear down mapping from pktcdvd device to CD-ROM device.
2944  */
2945 static int pkt_remove_dev(dev_t pkt_dev)
2946 {
2947         struct pktcdvd_device *pd;
2948         int idx;
2949         int ret = 0;
2950
2951         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2952
2953         for (idx = 0; idx < MAX_WRITERS; idx++) {
2954                 pd = pkt_devs[idx];
2955                 if (pd && (pd->pkt_dev == pkt_dev))
2956                         break;
2957         }
2958         if (idx == MAX_WRITERS) {
2959                 DPRINTK(DRIVER_NAME": dev not setup\n");
2960                 ret = -ENXIO;
2961                 goto out;
2962         }
2963
2964         if (pd->refcnt > 0) {
2965                 ret = -EBUSY;
2966                 goto out;
2967         }
2968         if (!IS_ERR(pd->cdrw.thread))
2969                 kthread_stop(pd->cdrw.thread);
2970
2971         pkt_devs[idx] = NULL;
2972
2973         pkt_debugfs_dev_remove(pd);
2974         pkt_sysfs_dev_remove(pd);
2975
2976         blkdev_put(pd->bdev);
2977
2978         remove_proc_entry(pd->name, pkt_proc);
2979         DPRINTK(DRIVER_NAME": writer %s unmapped\n", pd->name);
2980
2981         del_gendisk(pd->disk);
2982         blk_cleanup_queue(pd->disk->queue);
2983         put_disk(pd->disk);
2984
2985         mempool_destroy(pd->rb_pool);
2986         kfree(pd);
2987
2988         /* This is safe: open() is still holding a reference. */
2989         module_put(THIS_MODULE);
2990
2991 out:
2992         mutex_unlock(&ctl_mutex);
2993         return ret;
2994 }
2995
2996 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2997 {
2998         struct pktcdvd_device *pd;
2999
3000         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3001
3002         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
3003         if (pd) {
3004                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
3005                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
3006         } else {
3007                 ctrl_cmd->dev = 0;
3008                 ctrl_cmd->pkt_dev = 0;
3009         }
3010         ctrl_cmd->num_devices = MAX_WRITERS;
3011
3012         mutex_unlock(&ctl_mutex);
3013 }
3014
3015 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
3016 {
3017         void __user *argp = (void __user *)arg;
3018         struct pkt_ctrl_command ctrl_cmd;
3019         int ret = 0;
3020         dev_t pkt_dev = 0;
3021
3022         if (cmd != PACKET_CTRL_CMD)
3023                 return -ENOTTY;
3024
3025         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
3026                 return -EFAULT;
3027
3028         switch (ctrl_cmd.command) {
3029         case PKT_CTRL_CMD_SETUP:
3030                 if (!capable(CAP_SYS_ADMIN))
3031                         return -EPERM;
3032                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
3033                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
3034                 break;
3035         case PKT_CTRL_CMD_TEARDOWN:
3036                 if (!capable(CAP_SYS_ADMIN))
3037                         return -EPERM;
3038                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
3039                 break;
3040         case PKT_CTRL_CMD_STATUS:
3041                 pkt_get_status(&ctrl_cmd);
3042                 break;
3043         default:
3044                 return -ENOTTY;
3045         }
3046
3047         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
3048                 return -EFAULT;
3049         return ret;
3050 }
3051
3052
3053 static const struct file_operations pkt_ctl_fops = {
3054         .ioctl   = pkt_ctl_ioctl,
3055         .owner   = THIS_MODULE,
3056 };
3057
3058 static struct miscdevice pkt_misc = {
3059         .minor          = MISC_DYNAMIC_MINOR,
3060         .name           = DRIVER_NAME,
3061         .fops           = &pkt_ctl_fops
3062 };
3063
3064 static int __init pkt_init(void)
3065 {
3066         int ret;
3067
3068         mutex_init(&ctl_mutex);
3069
3070         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
3071                                         sizeof(struct packet_stacked_data));
3072         if (!psd_pool)
3073                 return -ENOMEM;
3074
3075         ret = register_blkdev(pktdev_major, DRIVER_NAME);
3076         if (ret < 0) {
3077                 printk(DRIVER_NAME": Unable to register block device\n");
3078                 goto out2;
3079         }
3080         if (!pktdev_major)
3081                 pktdev_major = ret;
3082
3083         ret = pkt_sysfs_init();
3084         if (ret)
3085                 goto out;
3086
3087         pkt_debugfs_init();
3088
3089         ret = misc_register(&pkt_misc);
3090         if (ret) {
3091                 printk(DRIVER_NAME": Unable to register misc device\n");
3092                 goto out_misc;
3093         }
3094
3095         pkt_proc = proc_mkdir(DRIVER_NAME, proc_root_driver);
3096
3097         return 0;
3098
3099 out_misc:
3100         pkt_debugfs_cleanup();
3101         pkt_sysfs_cleanup();
3102 out:
3103         unregister_blkdev(pktdev_major, DRIVER_NAME);
3104 out2:
3105         mempool_destroy(psd_pool);
3106         return ret;
3107 }
3108
3109 static void __exit pkt_exit(void)
3110 {
3111         remove_proc_entry(DRIVER_NAME, proc_root_driver);
3112         misc_deregister(&pkt_misc);
3113
3114         pkt_debugfs_cleanup();
3115         pkt_sysfs_cleanup();
3116
3117         unregister_blkdev(pktdev_major, DRIVER_NAME);
3118         mempool_destroy(psd_pool);
3119 }
3120
3121 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3122 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3123 MODULE_LICENSE("GPL");
3124
3125 module_init(pkt_init);
3126 module_exit(pkt_exit);