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 void pkt_end_io_read(struct bio *bio, int err)
1062 {
1063         struct packet_data *pkt = bio->bi_private;
1064         struct pktcdvd_device *pd = pkt->pd;
1065         BUG_ON(!pd);
1066
1067         VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
1068                 (unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
1069
1070         if (err)
1071                 atomic_inc(&pkt->io_errors);
1072         if (atomic_dec_and_test(&pkt->io_wait)) {
1073                 atomic_inc(&pkt->run_sm);
1074                 wake_up(&pd->wqueue);
1075         }
1076         pkt_bio_finished(pd);
1077 }
1078
1079 static void pkt_end_io_packet_write(struct bio *bio, int err)
1080 {
1081         struct packet_data *pkt = bio->bi_private;
1082         struct pktcdvd_device *pd = pkt->pd;
1083         BUG_ON(!pd);
1084
1085         VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
1086
1087         pd->stats.pkt_ended++;
1088
1089         pkt_bio_finished(pd);
1090         atomic_dec(&pkt->io_wait);
1091         atomic_inc(&pkt->run_sm);
1092         wake_up(&pd->wqueue);
1093 }
1094
1095 /*
1096  * Schedule reads for the holes in a packet
1097  */
1098 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1099 {
1100         int frames_read = 0;
1101         struct bio *bio;
1102         int f;
1103         char written[PACKET_MAX_SIZE];
1104
1105         BUG_ON(!pkt->orig_bios);
1106
1107         atomic_set(&pkt->io_wait, 0);
1108         atomic_set(&pkt->io_errors, 0);
1109
1110         /*
1111          * Figure out which frames we need to read before we can write.
1112          */
1113         memset(written, 0, sizeof(written));
1114         spin_lock(&pkt->lock);
1115         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1116                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1117                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1118                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1119                 BUG_ON(first_frame < 0);
1120                 BUG_ON(first_frame + num_frames > pkt->frames);
1121                 for (f = first_frame; f < first_frame + num_frames; f++)
1122                         written[f] = 1;
1123         }
1124         spin_unlock(&pkt->lock);
1125
1126         if (pkt->cache_valid) {
1127                 VPRINTK("pkt_gather_data: zone %llx cached\n",
1128                         (unsigned long long)pkt->sector);
1129                 goto out_account;
1130         }
1131
1132         /*
1133          * Schedule reads for missing parts of the packet.
1134          */
1135         for (f = 0; f < pkt->frames; f++) {
1136                 int p, offset;
1137                 if (written[f])
1138                         continue;
1139                 bio = pkt->r_bios[f];
1140                 bio_init(bio);
1141                 bio->bi_max_vecs = 1;
1142                 bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1143                 bio->bi_bdev = pd->bdev;
1144                 bio->bi_end_io = pkt_end_io_read;
1145                 bio->bi_private = pkt;
1146
1147                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1148                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1149                 VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
1150                         f, pkt->pages[p], offset);
1151                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1152                         BUG();
1153
1154                 atomic_inc(&pkt->io_wait);
1155                 bio->bi_rw = READ;
1156                 pkt_queue_bio(pd, bio);
1157                 frames_read++;
1158         }
1159
1160 out_account:
1161         VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
1162                 frames_read, (unsigned long long)pkt->sector);
1163         pd->stats.pkt_started++;
1164         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1165 }
1166
1167 /*
1168  * Find a packet matching zone, or the least recently used packet if
1169  * there is no match.
1170  */
1171 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1172 {
1173         struct packet_data *pkt;
1174
1175         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1176                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1177                         list_del_init(&pkt->list);
1178                         if (pkt->sector != zone)
1179                                 pkt->cache_valid = 0;
1180                         return pkt;
1181                 }
1182         }
1183         BUG();
1184         return NULL;
1185 }
1186
1187 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1188 {
1189         if (pkt->cache_valid) {
1190                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1191         } else {
1192                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1193         }
1194 }
1195
1196 /*
1197  * recover a failed write, query for relocation if possible
1198  *
1199  * returns 1 if recovery is possible, or 0 if not
1200  *
1201  */
1202 static int pkt_start_recovery(struct packet_data *pkt)
1203 {
1204         /*
1205          * FIXME. We need help from the file system to implement
1206          * recovery handling.
1207          */
1208         return 0;
1209 #if 0
1210         struct request *rq = pkt->rq;
1211         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1212         struct block_device *pkt_bdev;
1213         struct super_block *sb = NULL;
1214         unsigned long old_block, new_block;
1215         sector_t new_sector;
1216
1217         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1218         if (pkt_bdev) {
1219                 sb = get_super(pkt_bdev);
1220                 bdput(pkt_bdev);
1221         }
1222
1223         if (!sb)
1224                 return 0;
1225
1226         if (!sb->s_op || !sb->s_op->relocate_blocks)
1227                 goto out;
1228
1229         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1230         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1231                 goto out;
1232
1233         new_sector = new_block * (CD_FRAMESIZE >> 9);
1234         pkt->sector = new_sector;
1235
1236         pkt->bio->bi_sector = new_sector;
1237         pkt->bio->bi_next = NULL;
1238         pkt->bio->bi_flags = 1 << BIO_UPTODATE;
1239         pkt->bio->bi_idx = 0;
1240
1241         BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
1242         BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
1243         BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
1244         BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
1245         BUG_ON(pkt->bio->bi_private != pkt);
1246
1247         drop_super(sb);
1248         return 1;
1249
1250 out:
1251         drop_super(sb);
1252         return 0;
1253 #endif
1254 }
1255
1256 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1257 {
1258 #if PACKET_DEBUG > 1
1259         static const char *state_name[] = {
1260                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1261         };
1262         enum packet_data_state old_state = pkt->state;
1263         VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
1264                 state_name[old_state], state_name[state]);
1265 #endif
1266         pkt->state = state;
1267 }
1268
1269 /*
1270  * Scan the work queue to see if we can start a new packet.
1271  * returns non-zero if any work was done.
1272  */
1273 static int pkt_handle_queue(struct pktcdvd_device *pd)
1274 {
1275         struct packet_data *pkt, *p;
1276         struct bio *bio = NULL;
1277         sector_t zone = 0; /* Suppress gcc warning */
1278         struct pkt_rb_node *node, *first_node;
1279         struct rb_node *n;
1280         int wakeup;
1281
1282         VPRINTK("handle_queue\n");
1283
1284         atomic_set(&pd->scan_queue, 0);
1285
1286         if (list_empty(&pd->cdrw.pkt_free_list)) {
1287                 VPRINTK("handle_queue: no pkt\n");
1288                 return 0;
1289         }
1290
1291         /*
1292          * Try to find a zone we are not already working on.
1293          */
1294         spin_lock(&pd->lock);
1295         first_node = pkt_rbtree_find(pd, pd->current_sector);
1296         if (!first_node) {
1297                 n = rb_first(&pd->bio_queue);
1298                 if (n)
1299                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1300         }
1301         node = first_node;
1302         while (node) {
1303                 bio = node->bio;
1304                 zone = ZONE(bio->bi_sector, pd);
1305                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1306                         if (p->sector == zone) {
1307                                 bio = NULL;
1308                                 goto try_next_bio;
1309                         }
1310                 }
1311                 break;
1312 try_next_bio:
1313                 node = pkt_rbtree_next(node);
1314                 if (!node) {
1315                         n = rb_first(&pd->bio_queue);
1316                         if (n)
1317                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1318                 }
1319                 if (node == first_node)
1320                         node = NULL;
1321         }
1322         spin_unlock(&pd->lock);
1323         if (!bio) {
1324                 VPRINTK("handle_queue: no bio\n");
1325                 return 0;
1326         }
1327
1328         pkt = pkt_get_packet_data(pd, zone);
1329
1330         pd->current_sector = zone + pd->settings.size;
1331         pkt->sector = zone;
1332         BUG_ON(pkt->frames != pd->settings.size >> 2);
1333         pkt->write_size = 0;
1334
1335         /*
1336          * Scan work queue for bios in the same zone and link them
1337          * to this packet.
1338          */
1339         spin_lock(&pd->lock);
1340         VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
1341         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1342                 bio = node->bio;
1343                 VPRINTK("pkt_handle_queue: found zone=%llx\n",
1344                         (unsigned long long)ZONE(bio->bi_sector, pd));
1345                 if (ZONE(bio->bi_sector, pd) != zone)
1346                         break;
1347                 pkt_rbtree_erase(pd, node);
1348                 spin_lock(&pkt->lock);
1349                 pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
1350                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
1351                 spin_unlock(&pkt->lock);
1352         }
1353         /* check write congestion marks, and if bio_queue_size is
1354            below, wake up any waiters */
1355         wakeup = (pd->write_congestion_on > 0
1356                         && pd->bio_queue_size <= pd->write_congestion_off);
1357         spin_unlock(&pd->lock);
1358         if (wakeup)
1359                 clear_bdi_congested(&pd->disk->queue->backing_dev_info, WRITE);
1360
1361         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1362         pkt_set_state(pkt, PACKET_WAITING_STATE);
1363         atomic_set(&pkt->run_sm, 1);
1364
1365         spin_lock(&pd->cdrw.active_list_lock);
1366         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1367         spin_unlock(&pd->cdrw.active_list_lock);
1368
1369         return 1;
1370 }
1371
1372 /*
1373  * Assemble a bio to write one packet and queue the bio for processing
1374  * by the underlying block device.
1375  */
1376 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1377 {
1378         struct bio *bio;
1379         int f;
1380         int frames_write;
1381         struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1382
1383         for (f = 0; f < pkt->frames; f++) {
1384                 bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1385                 bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1386         }
1387
1388         /*
1389          * Fill-in bvec with data from orig_bios.
1390          */
1391         frames_write = 0;
1392         spin_lock(&pkt->lock);
1393         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1394                 int segment = bio->bi_idx;
1395                 int src_offs = 0;
1396                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1397                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1398                 BUG_ON(first_frame < 0);
1399                 BUG_ON(first_frame + num_frames > pkt->frames);
1400                 for (f = first_frame; f < first_frame + num_frames; f++) {
1401                         struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
1402
1403                         while (src_offs >= src_bvl->bv_len) {
1404                                 src_offs -= src_bvl->bv_len;
1405                                 segment++;
1406                                 BUG_ON(segment >= bio->bi_vcnt);
1407                                 src_bvl = bio_iovec_idx(bio, segment);
1408                         }
1409
1410                         if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
1411                                 bvec[f].bv_page = src_bvl->bv_page;
1412                                 bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
1413                         } else {
1414                                 pkt_copy_bio_data(bio, segment, src_offs,
1415                                                   bvec[f].bv_page, bvec[f].bv_offset);
1416                         }
1417                         src_offs += CD_FRAMESIZE;
1418                         frames_write++;
1419                 }
1420         }
1421         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1422         spin_unlock(&pkt->lock);
1423
1424         VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
1425                 frames_write, (unsigned long long)pkt->sector);
1426         BUG_ON(frames_write != pkt->write_size);
1427
1428         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1429                 pkt_make_local_copy(pkt, bvec);
1430                 pkt->cache_valid = 1;
1431         } else {
1432                 pkt->cache_valid = 0;
1433         }
1434
1435         /* Start the write request */
1436         bio_init(pkt->w_bio);
1437         pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
1438         pkt->w_bio->bi_sector = pkt->sector;
1439         pkt->w_bio->bi_bdev = pd->bdev;
1440         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1441         pkt->w_bio->bi_private = pkt;
1442         for (f = 0; f < pkt->frames; f++)
1443                 if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1444                         BUG();
1445         VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
1446
1447         atomic_set(&pkt->io_wait, 1);
1448         pkt->w_bio->bi_rw = WRITE;
1449         pkt_queue_bio(pd, pkt->w_bio);
1450 }
1451
1452 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1453 {
1454         struct bio *bio, *next;
1455
1456         if (!uptodate)
1457                 pkt->cache_valid = 0;
1458
1459         /* Finish all bios corresponding to this packet */
1460         bio = pkt->orig_bios;
1461         while (bio) {
1462                 next = bio->bi_next;
1463                 bio->bi_next = NULL;
1464                 bio_endio(bio, uptodate ? 0 : -EIO);
1465                 bio = next;
1466         }
1467         pkt->orig_bios = pkt->orig_bios_tail = NULL;
1468 }
1469
1470 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1471 {
1472         int uptodate;
1473
1474         VPRINTK("run_state_machine: pkt %d\n", pkt->id);
1475
1476         for (;;) {
1477                 switch (pkt->state) {
1478                 case PACKET_WAITING_STATE:
1479                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1480                                 return;
1481
1482                         pkt->sleep_time = 0;
1483                         pkt_gather_data(pd, pkt);
1484                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1485                         break;
1486
1487                 case PACKET_READ_WAIT_STATE:
1488                         if (atomic_read(&pkt->io_wait) > 0)
1489                                 return;
1490
1491                         if (atomic_read(&pkt->io_errors) > 0) {
1492                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1493                         } else {
1494                                 pkt_start_write(pd, pkt);
1495                         }
1496                         break;
1497
1498                 case PACKET_WRITE_WAIT_STATE:
1499                         if (atomic_read(&pkt->io_wait) > 0)
1500                                 return;
1501
1502                         if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1503                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1504                         } else {
1505                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1506                         }
1507                         break;
1508
1509                 case PACKET_RECOVERY_STATE:
1510                         if (pkt_start_recovery(pkt)) {
1511                                 pkt_start_write(pd, pkt);
1512                         } else {
1513                                 VPRINTK("No recovery possible\n");
1514                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1515                         }
1516                         break;
1517
1518                 case PACKET_FINISHED_STATE:
1519                         uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1520                         pkt_finish_packet(pkt, uptodate);
1521                         return;
1522
1523                 default:
1524                         BUG();
1525                         break;
1526                 }
1527         }
1528 }
1529
1530 static void pkt_handle_packets(struct pktcdvd_device *pd)
1531 {
1532         struct packet_data *pkt, *next;
1533
1534         VPRINTK("pkt_handle_packets\n");
1535
1536         /*
1537          * Run state machine for active packets
1538          */
1539         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1540                 if (atomic_read(&pkt->run_sm) > 0) {
1541                         atomic_set(&pkt->run_sm, 0);
1542                         pkt_run_state_machine(pd, pkt);
1543                 }
1544         }
1545
1546         /*
1547          * Move no longer active packets to the free list
1548          */
1549         spin_lock(&pd->cdrw.active_list_lock);
1550         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1551                 if (pkt->state == PACKET_FINISHED_STATE) {
1552                         list_del(&pkt->list);
1553                         pkt_put_packet_data(pd, pkt);
1554                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1555                         atomic_set(&pd->scan_queue, 1);
1556                 }
1557         }
1558         spin_unlock(&pd->cdrw.active_list_lock);
1559 }
1560
1561 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1562 {
1563         struct packet_data *pkt;
1564         int i;
1565
1566         for (i = 0; i < PACKET_NUM_STATES; i++)
1567                 states[i] = 0;
1568
1569         spin_lock(&pd->cdrw.active_list_lock);
1570         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1571                 states[pkt->state]++;
1572         }
1573         spin_unlock(&pd->cdrw.active_list_lock);
1574 }
1575
1576 /*
1577  * kcdrwd is woken up when writes have been queued for one of our
1578  * registered devices
1579  */
1580 static int kcdrwd(void *foobar)
1581 {
1582         struct pktcdvd_device *pd = foobar;
1583         struct packet_data *pkt;
1584         long min_sleep_time, residue;
1585
1586         set_user_nice(current, -20);
1587         set_freezable();
1588
1589         for (;;) {
1590                 DECLARE_WAITQUEUE(wait, current);
1591
1592                 /*
1593                  * Wait until there is something to do
1594                  */
1595                 add_wait_queue(&pd->wqueue, &wait);
1596                 for (;;) {
1597                         set_current_state(TASK_INTERRUPTIBLE);
1598
1599                         /* Check if we need to run pkt_handle_queue */
1600                         if (atomic_read(&pd->scan_queue) > 0)
1601                                 goto work_to_do;
1602
1603                         /* Check if we need to run the state machine for some packet */
1604                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1605                                 if (atomic_read(&pkt->run_sm) > 0)
1606                                         goto work_to_do;
1607                         }
1608
1609                         /* Check if we need to process the iosched queues */
1610                         if (atomic_read(&pd->iosched.attention) != 0)
1611                                 goto work_to_do;
1612
1613                         /* Otherwise, go to sleep */
1614                         if (PACKET_DEBUG > 1) {
1615                                 int states[PACKET_NUM_STATES];
1616                                 pkt_count_states(pd, states);
1617                                 VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1618                                         states[0], states[1], states[2], states[3],
1619                                         states[4], states[5]);
1620                         }
1621
1622                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1623                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1624                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1625                                         min_sleep_time = pkt->sleep_time;
1626                         }
1627
1628                         generic_unplug_device(bdev_get_queue(pd->bdev));
1629
1630                         VPRINTK("kcdrwd: sleeping\n");
1631                         residue = schedule_timeout(min_sleep_time);
1632                         VPRINTK("kcdrwd: wake up\n");
1633
1634                         /* make swsusp happy with our thread */
1635                         try_to_freeze();
1636
1637                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1638                                 if (!pkt->sleep_time)
1639                                         continue;
1640                                 pkt->sleep_time -= min_sleep_time - residue;
1641                                 if (pkt->sleep_time <= 0) {
1642                                         pkt->sleep_time = 0;
1643                                         atomic_inc(&pkt->run_sm);
1644                                 }
1645                         }
1646
1647                         if (kthread_should_stop())
1648                                 break;
1649                 }
1650 work_to_do:
1651                 set_current_state(TASK_RUNNING);
1652                 remove_wait_queue(&pd->wqueue, &wait);
1653
1654                 if (kthread_should_stop())
1655                         break;
1656
1657                 /*
1658                  * if pkt_handle_queue returns true, we can queue
1659                  * another request.
1660                  */
1661                 while (pkt_handle_queue(pd))
1662                         ;
1663
1664                 /*
1665                  * Handle packet state machine
1666                  */
1667                 pkt_handle_packets(pd);
1668
1669                 /*
1670                  * Handle iosched queues
1671                  */
1672                 pkt_iosched_process_queue(pd);
1673         }
1674
1675         return 0;
1676 }
1677
1678 static void pkt_print_settings(struct pktcdvd_device *pd)
1679 {
1680         printk(DRIVER_NAME": %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
1681         printk("%u blocks, ", pd->settings.size >> 2);
1682         printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
1683 }
1684
1685 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1686 {
1687         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1688
1689         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1690         cgc->cmd[2] = page_code | (page_control << 6);
1691         cgc->cmd[7] = cgc->buflen >> 8;
1692         cgc->cmd[8] = cgc->buflen & 0xff;
1693         cgc->data_direction = CGC_DATA_READ;
1694         return pkt_generic_packet(pd, cgc);
1695 }
1696
1697 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1698 {
1699         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1700         memset(cgc->buffer, 0, 2);
1701         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1702         cgc->cmd[1] = 0x10;             /* PF */
1703         cgc->cmd[7] = cgc->buflen >> 8;
1704         cgc->cmd[8] = cgc->buflen & 0xff;
1705         cgc->data_direction = CGC_DATA_WRITE;
1706         return pkt_generic_packet(pd, cgc);
1707 }
1708
1709 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1710 {
1711         struct packet_command cgc;
1712         int ret;
1713
1714         /* set up command and get the disc info */
1715         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1716         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1717         cgc.cmd[8] = cgc.buflen = 2;
1718         cgc.quiet = 1;
1719
1720         if ((ret = pkt_generic_packet(pd, &cgc)))
1721                 return ret;
1722
1723         /* not all drives have the same disc_info length, so requeue
1724          * packet with the length the drive tells us it can supply
1725          */
1726         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1727                      sizeof(di->disc_information_length);
1728
1729         if (cgc.buflen > sizeof(disc_information))
1730                 cgc.buflen = sizeof(disc_information);
1731
1732         cgc.cmd[8] = cgc.buflen;
1733         return pkt_generic_packet(pd, &cgc);
1734 }
1735
1736 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1737 {
1738         struct packet_command cgc;
1739         int ret;
1740
1741         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1742         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1743         cgc.cmd[1] = type & 3;
1744         cgc.cmd[4] = (track & 0xff00) >> 8;
1745         cgc.cmd[5] = track & 0xff;
1746         cgc.cmd[8] = 8;
1747         cgc.quiet = 1;
1748
1749         if ((ret = pkt_generic_packet(pd, &cgc)))
1750                 return ret;
1751
1752         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1753                      sizeof(ti->track_information_length);
1754
1755         if (cgc.buflen > sizeof(track_information))
1756                 cgc.buflen = sizeof(track_information);
1757
1758         cgc.cmd[8] = cgc.buflen;
1759         return pkt_generic_packet(pd, &cgc);
1760 }
1761
1762 static int pkt_get_last_written(struct pktcdvd_device *pd, long *last_written)
1763 {
1764         disc_information di;
1765         track_information ti;
1766         __u32 last_track;
1767         int ret = -1;
1768
1769         if ((ret = pkt_get_disc_info(pd, &di)))
1770                 return ret;
1771
1772         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1773         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1774                 return ret;
1775
1776         /* if this track is blank, try the previous. */
1777         if (ti.blank) {
1778                 last_track--;
1779                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1780                         return ret;
1781         }
1782
1783         /* if last recorded field is valid, return it. */
1784         if (ti.lra_v) {
1785                 *last_written = be32_to_cpu(ti.last_rec_address);
1786         } else {
1787                 /* make it up instead */
1788                 *last_written = be32_to_cpu(ti.track_start) +
1789                                 be32_to_cpu(ti.track_size);
1790                 if (ti.free_blocks)
1791                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1792         }
1793         return 0;
1794 }
1795
1796 /*
1797  * write mode select package based on pd->settings
1798  */
1799 static int pkt_set_write_settings(struct pktcdvd_device *pd)
1800 {
1801         struct packet_command cgc;
1802         struct request_sense sense;
1803         write_param_page *wp;
1804         char buffer[128];
1805         int ret, size;
1806
1807         /* doesn't apply to DVD+RW or DVD-RAM */
1808         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1809                 return 0;
1810
1811         memset(buffer, 0, sizeof(buffer));
1812         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1813         cgc.sense = &sense;
1814         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1815                 pkt_dump_sense(&cgc);
1816                 return ret;
1817         }
1818
1819         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1820         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1821         if (size > sizeof(buffer))
1822                 size = sizeof(buffer);
1823
1824         /*
1825          * now get it all
1826          */
1827         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1828         cgc.sense = &sense;
1829         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1830                 pkt_dump_sense(&cgc);
1831                 return ret;
1832         }
1833
1834         /*
1835          * write page is offset header + block descriptor length
1836          */
1837         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1838
1839         wp->fp = pd->settings.fp;
1840         wp->track_mode = pd->settings.track_mode;
1841         wp->write_type = pd->settings.write_type;
1842         wp->data_block_type = pd->settings.block_mode;
1843
1844         wp->multi_session = 0;
1845
1846 #ifdef PACKET_USE_LS
1847         wp->link_size = 7;
1848         wp->ls_v = 1;
1849 #endif
1850
1851         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1852                 wp->session_format = 0;
1853                 wp->subhdr2 = 0x20;
1854         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1855                 wp->session_format = 0x20;
1856                 wp->subhdr2 = 8;
1857 #if 0
1858                 wp->mcn[0] = 0x80;
1859                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1860 #endif
1861         } else {
1862                 /*
1863                  * paranoia
1864                  */
1865                 printk(DRIVER_NAME": write mode wrong %d\n", wp->data_block_type);
1866                 return 1;
1867         }
1868         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1869
1870         cgc.buflen = cgc.cmd[8] = size;
1871         if ((ret = pkt_mode_select(pd, &cgc))) {
1872                 pkt_dump_sense(&cgc);
1873                 return ret;
1874         }
1875
1876         pkt_print_settings(pd);
1877         return 0;
1878 }
1879
1880 /*
1881  * 1 -- we can write to this track, 0 -- we can't
1882  */
1883 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1884 {
1885         switch (pd->mmc3_profile) {
1886                 case 0x1a: /* DVD+RW */
1887                 case 0x12: /* DVD-RAM */
1888                         /* The track is always writable on DVD+RW/DVD-RAM */
1889                         return 1;
1890                 default:
1891                         break;
1892         }
1893
1894         if (!ti->packet || !ti->fp)
1895                 return 0;
1896
1897         /*
1898          * "good" settings as per Mt Fuji.
1899          */
1900         if (ti->rt == 0 && ti->blank == 0)
1901                 return 1;
1902
1903         if (ti->rt == 0 && ti->blank == 1)
1904                 return 1;
1905
1906         if (ti->rt == 1 && ti->blank == 0)
1907                 return 1;
1908
1909         printk(DRIVER_NAME": bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1910         return 0;
1911 }
1912
1913 /*
1914  * 1 -- we can write to this disc, 0 -- we can't
1915  */
1916 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1917 {
1918         switch (pd->mmc3_profile) {
1919                 case 0x0a: /* CD-RW */
1920                 case 0xffff: /* MMC3 not supported */
1921                         break;
1922                 case 0x1a: /* DVD+RW */
1923                 case 0x13: /* DVD-RW */
1924                 case 0x12: /* DVD-RAM */
1925                         return 1;
1926                 default:
1927                         VPRINTK(DRIVER_NAME": Wrong disc profile (%x)\n", pd->mmc3_profile);
1928                         return 0;
1929         }
1930
1931         /*
1932          * for disc type 0xff we should probably reserve a new track.
1933          * but i'm not sure, should we leave this to user apps? probably.
1934          */
1935         if (di->disc_type == 0xff) {
1936                 printk(DRIVER_NAME": Unknown disc. No track?\n");
1937                 return 0;
1938         }
1939
1940         if (di->disc_type != 0x20 && di->disc_type != 0) {
1941                 printk(DRIVER_NAME": Wrong disc type (%x)\n", di->disc_type);
1942                 return 0;
1943         }
1944
1945         if (di->erasable == 0) {
1946                 printk(DRIVER_NAME": Disc not erasable\n");
1947                 return 0;
1948         }
1949
1950         if (di->border_status == PACKET_SESSION_RESERVED) {
1951                 printk(DRIVER_NAME": Can't write to last track (reserved)\n");
1952                 return 0;
1953         }
1954
1955         return 1;
1956 }
1957
1958 static int pkt_probe_settings(struct pktcdvd_device *pd)
1959 {
1960         struct packet_command cgc;
1961         unsigned char buf[12];
1962         disc_information di;
1963         track_information ti;
1964         int ret, track;
1965
1966         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1967         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1968         cgc.cmd[8] = 8;
1969         ret = pkt_generic_packet(pd, &cgc);
1970         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1971
1972         memset(&di, 0, sizeof(disc_information));
1973         memset(&ti, 0, sizeof(track_information));
1974
1975         if ((ret = pkt_get_disc_info(pd, &di))) {
1976                 printk("failed get_disc\n");
1977                 return ret;
1978         }
1979
1980         if (!pkt_writable_disc(pd, &di))
1981                 return -EROFS;
1982
1983         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1984
1985         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1986         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1987                 printk(DRIVER_NAME": failed get_track\n");
1988                 return ret;
1989         }
1990
1991         if (!pkt_writable_track(pd, &ti)) {
1992                 printk(DRIVER_NAME": can't write to this track\n");
1993                 return -EROFS;
1994         }
1995
1996         /*
1997          * we keep packet size in 512 byte units, makes it easier to
1998          * deal with request calculations.
1999          */
2000         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
2001         if (pd->settings.size == 0) {
2002                 printk(DRIVER_NAME": detected zero packet size!\n");
2003                 return -ENXIO;
2004         }
2005         if (pd->settings.size > PACKET_MAX_SECTORS) {
2006                 printk(DRIVER_NAME": packet size is too big\n");
2007                 return -EROFS;
2008         }
2009         pd->settings.fp = ti.fp;
2010         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
2011
2012         if (ti.nwa_v) {
2013                 pd->nwa = be32_to_cpu(ti.next_writable);
2014                 set_bit(PACKET_NWA_VALID, &pd->flags);
2015         }
2016
2017         /*
2018          * in theory we could use lra on -RW media as well and just zero
2019          * blocks that haven't been written yet, but in practice that
2020          * is just a no-go. we'll use that for -R, naturally.
2021          */
2022         if (ti.lra_v) {
2023                 pd->lra = be32_to_cpu(ti.last_rec_address);
2024                 set_bit(PACKET_LRA_VALID, &pd->flags);
2025         } else {
2026                 pd->lra = 0xffffffff;
2027                 set_bit(PACKET_LRA_VALID, &pd->flags);
2028         }
2029
2030         /*
2031          * fine for now
2032          */
2033         pd->settings.link_loss = 7;
2034         pd->settings.write_type = 0;    /* packet */
2035         pd->settings.track_mode = ti.track_mode;
2036
2037         /*
2038          * mode1 or mode2 disc
2039          */
2040         switch (ti.data_mode) {
2041                 case PACKET_MODE1:
2042                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
2043                         break;
2044                 case PACKET_MODE2:
2045                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
2046                         break;
2047                 default:
2048                         printk(DRIVER_NAME": unknown data mode\n");
2049                         return -EROFS;
2050         }
2051         return 0;
2052 }
2053
2054 /*
2055  * enable/disable write caching on drive
2056  */
2057 static int pkt_write_caching(struct pktcdvd_device *pd, int set)
2058 {
2059         struct packet_command cgc;
2060         struct request_sense sense;
2061         unsigned char buf[64];
2062         int ret;
2063
2064         memset(buf, 0, sizeof(buf));
2065         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
2066         cgc.sense = &sense;
2067         cgc.buflen = pd->mode_offset + 12;
2068
2069         /*
2070          * caching mode page might not be there, so quiet this command
2071          */
2072         cgc.quiet = 1;
2073
2074         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
2075                 return ret;
2076
2077         buf[pd->mode_offset + 10] |= (!!set << 2);
2078
2079         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
2080         ret = pkt_mode_select(pd, &cgc);
2081         if (ret) {
2082                 printk(DRIVER_NAME": write caching control failed\n");
2083                 pkt_dump_sense(&cgc);
2084         } else if (!ret && set)
2085                 printk(DRIVER_NAME": enabled write caching on %s\n", pd->name);
2086         return ret;
2087 }
2088
2089 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
2090 {
2091         struct packet_command cgc;
2092
2093         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2094         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
2095         cgc.cmd[4] = lockflag ? 1 : 0;
2096         return pkt_generic_packet(pd, &cgc);
2097 }
2098
2099 /*
2100  * Returns drive maximum write speed
2101  */
2102 static int pkt_get_max_speed(struct pktcdvd_device *pd, unsigned *write_speed)
2103 {
2104         struct packet_command cgc;
2105         struct request_sense sense;
2106         unsigned char buf[256+18];
2107         unsigned char *cap_buf;
2108         int ret, offset;
2109
2110         memset(buf, 0, sizeof(buf));
2111         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
2112         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
2113         cgc.sense = &sense;
2114
2115         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2116         if (ret) {
2117                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2118                              sizeof(struct mode_page_header);
2119                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2120                 if (ret) {
2121                         pkt_dump_sense(&cgc);
2122                         return ret;
2123                 }
2124         }
2125
2126         offset = 20;                        /* Obsoleted field, used by older drives */
2127         if (cap_buf[1] >= 28)
2128                 offset = 28;                /* Current write speed selected */
2129         if (cap_buf[1] >= 30) {
2130                 /* If the drive reports at least one "Logical Unit Write
2131                  * Speed Performance Descriptor Block", use the information
2132                  * in the first block. (contains the highest speed)
2133                  */
2134                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2135                 if (num_spdb > 0)
2136                         offset = 34;
2137         }
2138
2139         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2140         return 0;
2141 }
2142
2143 /* These tables from cdrecord - I don't have orange book */
2144 /* standard speed CD-RW (1-4x) */
2145 static char clv_to_speed[16] = {
2146         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2147            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2148 };
2149 /* high speed CD-RW (-10x) */
2150 static char hs_clv_to_speed[16] = {
2151         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2152            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2153 };
2154 /* ultra high speed CD-RW */
2155 static char us_clv_to_speed[16] = {
2156         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2157            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2158 };
2159
2160 /*
2161  * reads the maximum media speed from ATIP
2162  */
2163 static int pkt_media_speed(struct pktcdvd_device *pd, unsigned *speed)
2164 {
2165         struct packet_command cgc;
2166         struct request_sense sense;
2167         unsigned char buf[64];
2168         unsigned int size, st, sp;
2169         int ret;
2170
2171         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2172         cgc.sense = &sense;
2173         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2174         cgc.cmd[1] = 2;
2175         cgc.cmd[2] = 4; /* READ ATIP */
2176         cgc.cmd[8] = 2;
2177         ret = pkt_generic_packet(pd, &cgc);
2178         if (ret) {
2179                 pkt_dump_sense(&cgc);
2180                 return ret;
2181         }
2182         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2183         if (size > sizeof(buf))
2184                 size = sizeof(buf);
2185
2186         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2187         cgc.sense = &sense;
2188         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2189         cgc.cmd[1] = 2;
2190         cgc.cmd[2] = 4;
2191         cgc.cmd[8] = size;
2192         ret = pkt_generic_packet(pd, &cgc);
2193         if (ret) {
2194                 pkt_dump_sense(&cgc);
2195                 return ret;
2196         }
2197
2198         if (!buf[6] & 0x40) {
2199                 printk(DRIVER_NAME": Disc type is not CD-RW\n");
2200                 return 1;
2201         }
2202         if (!buf[6] & 0x4) {
2203                 printk(DRIVER_NAME": A1 values on media are not valid, maybe not CDRW?\n");
2204                 return 1;
2205         }
2206
2207         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2208
2209         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2210
2211         /* Info from cdrecord */
2212         switch (st) {
2213                 case 0: /* standard speed */
2214                         *speed = clv_to_speed[sp];
2215                         break;
2216                 case 1: /* high speed */
2217                         *speed = hs_clv_to_speed[sp];
2218                         break;
2219                 case 2: /* ultra high speed */
2220                         *speed = us_clv_to_speed[sp];
2221                         break;
2222                 default:
2223                         printk(DRIVER_NAME": Unknown disc sub-type %d\n",st);
2224                         return 1;
2225         }
2226         if (*speed) {
2227                 printk(DRIVER_NAME": Max. media speed: %d\n",*speed);
2228                 return 0;
2229         } else {
2230                 printk(DRIVER_NAME": Unknown speed %d for sub-type %d\n",sp,st);
2231                 return 1;
2232         }
2233 }
2234
2235 static int pkt_perform_opc(struct pktcdvd_device *pd)
2236 {
2237         struct packet_command cgc;
2238         struct request_sense sense;
2239         int ret;
2240
2241         VPRINTK(DRIVER_NAME": Performing OPC\n");
2242
2243         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2244         cgc.sense = &sense;
2245         cgc.timeout = 60*HZ;
2246         cgc.cmd[0] = GPCMD_SEND_OPC;
2247         cgc.cmd[1] = 1;
2248         if ((ret = pkt_generic_packet(pd, &cgc)))
2249                 pkt_dump_sense(&cgc);
2250         return ret;
2251 }
2252
2253 static int pkt_open_write(struct pktcdvd_device *pd)
2254 {
2255         int ret;
2256         unsigned int write_speed, media_write_speed, read_speed;
2257
2258         if ((ret = pkt_probe_settings(pd))) {
2259                 VPRINTK(DRIVER_NAME": %s failed probe\n", pd->name);
2260                 return ret;
2261         }
2262
2263         if ((ret = pkt_set_write_settings(pd))) {
2264                 DPRINTK(DRIVER_NAME": %s failed saving write settings\n", pd->name);
2265                 return -EIO;
2266         }
2267
2268         pkt_write_caching(pd, USE_WCACHING);
2269
2270         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2271                 write_speed = 16 * 177;
2272         switch (pd->mmc3_profile) {
2273                 case 0x13: /* DVD-RW */
2274                 case 0x1a: /* DVD+RW */
2275                 case 0x12: /* DVD-RAM */
2276                         DPRINTK(DRIVER_NAME": write speed %ukB/s\n", write_speed);
2277                         break;
2278                 default:
2279                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2280                                 media_write_speed = 16;
2281                         write_speed = min(write_speed, media_write_speed * 177);
2282                         DPRINTK(DRIVER_NAME": write speed %ux\n", write_speed / 176);
2283                         break;
2284         }
2285         read_speed = write_speed;
2286
2287         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2288                 DPRINTK(DRIVER_NAME": %s couldn't set write speed\n", pd->name);
2289                 return -EIO;
2290         }
2291         pd->write_speed = write_speed;
2292         pd->read_speed = read_speed;
2293
2294         if ((ret = pkt_perform_opc(pd))) {
2295                 DPRINTK(DRIVER_NAME": %s Optimum Power Calibration failed\n", pd->name);
2296         }
2297
2298         return 0;
2299 }
2300
2301 /*
2302  * called at open time.
2303  */
2304 static int pkt_open_dev(struct pktcdvd_device *pd, int write)
2305 {
2306         int ret;
2307         long lba;
2308         struct request_queue *q;
2309
2310         /*
2311          * We need to re-open the cdrom device without O_NONBLOCK to be able
2312          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2313          * so bdget() can't fail.
2314          */
2315         bdget(pd->bdev->bd_dev);
2316         if ((ret = blkdev_get(pd->bdev, FMODE_READ, O_RDONLY)))
2317                 goto out;
2318
2319         if ((ret = bd_claim(pd->bdev, pd)))
2320                 goto out_putdev;
2321
2322         if ((ret = pkt_get_last_written(pd, &lba))) {
2323                 printk(DRIVER_NAME": pkt_get_last_written failed\n");
2324                 goto out_unclaim;
2325         }
2326
2327         set_capacity(pd->disk, lba << 2);
2328         set_capacity(pd->bdev->bd_disk, lba << 2);
2329         bd_set_size(pd->bdev, (loff_t)lba << 11);
2330
2331         q = bdev_get_queue(pd->bdev);
2332         if (write) {
2333                 if ((ret = pkt_open_write(pd)))
2334                         goto out_unclaim;
2335                 /*
2336                  * Some CDRW drives can not handle writes larger than one packet,
2337                  * even if the size is a multiple of the packet size.
2338                  */
2339                 spin_lock_irq(q->queue_lock);
2340                 blk_queue_max_sectors(q, pd->settings.size);
2341                 spin_unlock_irq(q->queue_lock);
2342                 set_bit(PACKET_WRITABLE, &pd->flags);
2343         } else {
2344                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2345                 clear_bit(PACKET_WRITABLE, &pd->flags);
2346         }
2347
2348         if ((ret = pkt_set_segment_merging(pd, q)))
2349                 goto out_unclaim;
2350
2351         if (write) {
2352                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2353                         printk(DRIVER_NAME": not enough memory for buffers\n");
2354                         ret = -ENOMEM;
2355                         goto out_unclaim;
2356                 }
2357                 printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
2358         }
2359
2360         return 0;
2361
2362 out_unclaim:
2363         bd_release(pd->bdev);
2364 out_putdev:
2365         blkdev_put(pd->bdev);
2366 out:
2367         return ret;
2368 }
2369
2370 /*
2371  * called when the device is closed. makes sure that the device flushes
2372  * the internal cache before we close.
2373  */
2374 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2375 {
2376         if (flush && pkt_flush_cache(pd))
2377                 DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
2378
2379         pkt_lock_door(pd, 0);
2380
2381         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2382         bd_release(pd->bdev);
2383         blkdev_put(pd->bdev);
2384
2385         pkt_shrink_pktlist(pd);
2386 }
2387
2388 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
2389 {
2390         if (dev_minor >= MAX_WRITERS)
2391                 return NULL;
2392         return pkt_devs[dev_minor];
2393 }
2394
2395 static int pkt_open(struct inode *inode, struct file *file)
2396 {
2397         struct pktcdvd_device *pd = NULL;
2398         int ret;
2399
2400         VPRINTK(DRIVER_NAME": entering open\n");
2401
2402         mutex_lock(&ctl_mutex);
2403         pd = pkt_find_dev_from_minor(iminor(inode));
2404         if (!pd) {
2405                 ret = -ENODEV;
2406                 goto out;
2407         }
2408         BUG_ON(pd->refcnt < 0);
2409
2410         pd->refcnt++;
2411         if (pd->refcnt > 1) {
2412                 if ((file->f_mode & FMODE_WRITE) &&
2413                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2414                         ret = -EBUSY;
2415                         goto out_dec;
2416                 }
2417         } else {
2418                 ret = pkt_open_dev(pd, file->f_mode & FMODE_WRITE);
2419                 if (ret)
2420                         goto out_dec;
2421                 /*
2422                  * needed here as well, since ext2 (among others) may change
2423                  * the blocksize at mount time
2424                  */
2425                 set_blocksize(inode->i_bdev, CD_FRAMESIZE);
2426         }
2427
2428         mutex_unlock(&ctl_mutex);
2429         return 0;
2430
2431 out_dec:
2432         pd->refcnt--;
2433 out:
2434         VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
2435         mutex_unlock(&ctl_mutex);
2436         return ret;
2437 }
2438
2439 static int pkt_close(struct inode *inode, struct file *file)
2440 {
2441         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2442         int ret = 0;
2443
2444         mutex_lock(&ctl_mutex);
2445         pd->refcnt--;
2446         BUG_ON(pd->refcnt < 0);
2447         if (pd->refcnt == 0) {
2448                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2449                 pkt_release_dev(pd, flush);
2450         }
2451         mutex_unlock(&ctl_mutex);
2452         return ret;
2453 }
2454
2455
2456 static void pkt_end_io_read_cloned(struct bio *bio, int err)
2457 {
2458         struct packet_stacked_data *psd = bio->bi_private;
2459         struct pktcdvd_device *pd = psd->pd;
2460
2461         bio_put(bio);
2462         bio_endio(psd->bio, err);
2463         mempool_free(psd, psd_pool);
2464         pkt_bio_finished(pd);
2465 }
2466
2467 static int pkt_make_request(struct request_queue *q, struct bio *bio)
2468 {
2469         struct pktcdvd_device *pd;
2470         char b[BDEVNAME_SIZE];
2471         sector_t zone;
2472         struct packet_data *pkt;
2473         int was_empty, blocked_bio;
2474         struct pkt_rb_node *node;
2475
2476         pd = q->queuedata;
2477         if (!pd) {
2478                 printk(DRIVER_NAME": %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
2479                 goto end_io;
2480         }
2481
2482         /*
2483          * Clone READ bios so we can have our own bi_end_io callback.
2484          */
2485         if (bio_data_dir(bio) == READ) {
2486                 struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2487                 struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2488
2489                 psd->pd = pd;
2490                 psd->bio = bio;
2491                 cloned_bio->bi_bdev = pd->bdev;
2492                 cloned_bio->bi_private = psd;
2493                 cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2494                 pd->stats.secs_r += bio->bi_size >> 9;
2495                 pkt_queue_bio(pd, cloned_bio);
2496                 return 0;
2497         }
2498
2499         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2500                 printk(DRIVER_NAME": WRITE for ro device %s (%llu)\n",
2501                         pd->name, (unsigned long long)bio->bi_sector);
2502                 goto end_io;
2503         }
2504
2505         if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
2506                 printk(DRIVER_NAME": wrong bio size\n");
2507                 goto end_io;
2508         }
2509
2510         blk_queue_bounce(q, &bio);
2511
2512         zone = ZONE(bio->bi_sector, pd);
2513         VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
2514                 (unsigned long long)bio->bi_sector,
2515                 (unsigned long long)(bio->bi_sector + bio_sectors(bio)));
2516
2517         /* Check if we have to split the bio */
2518         {
2519                 struct bio_pair *bp;
2520                 sector_t last_zone;
2521                 int first_sectors;
2522
2523                 last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
2524                 if (last_zone != zone) {
2525                         BUG_ON(last_zone != zone + pd->settings.size);
2526                         first_sectors = last_zone - bio->bi_sector;
2527                         bp = bio_split(bio, bio_split_pool, first_sectors);
2528                         BUG_ON(!bp);
2529                         pkt_make_request(q, &bp->bio1);
2530                         pkt_make_request(q, &bp->bio2);
2531                         bio_pair_release(bp);
2532                         return 0;
2533                 }
2534         }
2535
2536         /*
2537          * If we find a matching packet in state WAITING or READ_WAIT, we can
2538          * just append this bio to that packet.
2539          */
2540         spin_lock(&pd->cdrw.active_list_lock);
2541         blocked_bio = 0;
2542         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2543                 if (pkt->sector == zone) {
2544                         spin_lock(&pkt->lock);
2545                         if ((pkt->state == PACKET_WAITING_STATE) ||
2546                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2547                                 pkt_add_list_last(bio, &pkt->orig_bios,
2548                                                   &pkt->orig_bios_tail);
2549                                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
2550                                 if ((pkt->write_size >= pkt->frames) &&
2551                                     (pkt->state == PACKET_WAITING_STATE)) {
2552                                         atomic_inc(&pkt->run_sm);
2553                                         wake_up(&pd->wqueue);
2554                                 }
2555                                 spin_unlock(&pkt->lock);
2556                                 spin_unlock(&pd->cdrw.active_list_lock);
2557                                 return 0;
2558                         } else {
2559                                 blocked_bio = 1;
2560                         }
2561                         spin_unlock(&pkt->lock);
2562                 }
2563         }
2564         spin_unlock(&pd->cdrw.active_list_lock);
2565
2566         /*
2567          * Test if there is enough room left in the bio work queue
2568          * (queue size >= congestion on mark).
2569          * If not, wait till the work queue size is below the congestion off mark.
2570          */
2571         spin_lock(&pd->lock);
2572         if (pd->write_congestion_on > 0
2573             && pd->bio_queue_size >= pd->write_congestion_on) {
2574                 set_bdi_congested(&q->backing_dev_info, WRITE);
2575                 do {
2576                         spin_unlock(&pd->lock);
2577                         congestion_wait(WRITE, HZ);
2578                         spin_lock(&pd->lock);
2579                 } while(pd->bio_queue_size > pd->write_congestion_off);
2580         }
2581         spin_unlock(&pd->lock);
2582
2583         /*
2584          * No matching packet found. Store the bio in the work queue.
2585          */
2586         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2587         node->bio = bio;
2588         spin_lock(&pd->lock);
2589         BUG_ON(pd->bio_queue_size < 0);
2590         was_empty = (pd->bio_queue_size == 0);
2591         pkt_rbtree_insert(pd, node);
2592         spin_unlock(&pd->lock);
2593
2594         /*
2595          * Wake up the worker thread.
2596          */
2597         atomic_set(&pd->scan_queue, 1);
2598         if (was_empty) {
2599                 /* This wake_up is required for correct operation */
2600                 wake_up(&pd->wqueue);
2601         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2602                 /*
2603                  * This wake up is not required for correct operation,
2604                  * but improves performance in some cases.
2605                  */
2606                 wake_up(&pd->wqueue);
2607         }
2608         return 0;
2609 end_io:
2610         bio_io_error(bio);
2611         return 0;
2612 }
2613
2614
2615
2616 static int pkt_merge_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *bvec)
2617 {
2618         struct pktcdvd_device *pd = q->queuedata;
2619         sector_t zone = ZONE(bio->bi_sector, pd);
2620         int used = ((bio->bi_sector - zone) << 9) + bio->bi_size;
2621         int remaining = (pd->settings.size << 9) - used;
2622         int remaining2;
2623
2624         /*
2625          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2626          * boundary, pkt_make_request() will split the bio.
2627          */
2628         remaining2 = PAGE_SIZE - bio->bi_size;
2629         remaining = max(remaining, remaining2);
2630
2631         BUG_ON(remaining < 0);
2632         return remaining;
2633 }
2634
2635 static void pkt_init_queue(struct pktcdvd_device *pd)
2636 {
2637         struct request_queue *q = pd->disk->queue;
2638
2639         blk_queue_make_request(q, pkt_make_request);
2640         blk_queue_hardsect_size(q, CD_FRAMESIZE);
2641         blk_queue_max_sectors(q, PACKET_MAX_SECTORS);
2642         blk_queue_merge_bvec(q, pkt_merge_bvec);
2643         q->queuedata = pd;
2644 }
2645
2646 static int pkt_seq_show(struct seq_file *m, void *p)
2647 {
2648         struct pktcdvd_device *pd = m->private;
2649         char *msg;
2650         char bdev_buf[BDEVNAME_SIZE];
2651         int states[PACKET_NUM_STATES];
2652
2653         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2654                    bdevname(pd->bdev, bdev_buf));
2655
2656         seq_printf(m, "\nSettings:\n");
2657         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2658
2659         if (pd->settings.write_type == 0)
2660                 msg = "Packet";
2661         else
2662                 msg = "Unknown";
2663         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2664
2665         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2666         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2667
2668         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2669
2670         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2671                 msg = "Mode 1";
2672         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2673                 msg = "Mode 2";
2674         else
2675                 msg = "Unknown";
2676         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2677
2678         seq_printf(m, "\nStatistics:\n");
2679         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2680         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2681         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2682         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2683         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2684
2685         seq_printf(m, "\nMisc:\n");
2686         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2687         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2688         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2689         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2690         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2691         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2692
2693         seq_printf(m, "\nQueue state:\n");
2694         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2695         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2696         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2697
2698         pkt_count_states(pd, states);
2699         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2700                    states[0], states[1], states[2], states[3], states[4], states[5]);
2701
2702         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2703                         pd->write_congestion_off,
2704                         pd->write_congestion_on);
2705         return 0;
2706 }
2707
2708 static int pkt_seq_open(struct inode *inode, struct file *file)
2709 {
2710         return single_open(file, pkt_seq_show, PDE(inode)->data);
2711 }
2712
2713 static const struct file_operations pkt_proc_fops = {
2714         .open   = pkt_seq_open,
2715         .read   = seq_read,
2716         .llseek = seq_lseek,
2717         .release = single_release
2718 };
2719
2720 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2721 {
2722         int i;
2723         int ret = 0;
2724         char b[BDEVNAME_SIZE];
2725         struct proc_dir_entry *proc;
2726         struct block_device *bdev;
2727
2728         if (pd->pkt_dev == dev) {
2729                 printk(DRIVER_NAME": Recursive setup not allowed\n");
2730                 return -EBUSY;
2731         }
2732         for (i = 0; i < MAX_WRITERS; i++) {
2733                 struct pktcdvd_device *pd2 = pkt_devs[i];
2734                 if (!pd2)
2735                         continue;
2736                 if (pd2->bdev->bd_dev == dev) {
2737                         printk(DRIVER_NAME": %s already setup\n", bdevname(pd2->bdev, b));
2738                         return -EBUSY;
2739                 }
2740                 if (pd2->pkt_dev == dev) {
2741                         printk(DRIVER_NAME": Can't chain pktcdvd devices\n");
2742                         return -EBUSY;
2743                 }
2744         }
2745
2746         bdev = bdget(dev);
2747         if (!bdev)
2748                 return -ENOMEM;
2749         ret = blkdev_get(bdev, FMODE_READ, O_RDONLY | O_NONBLOCK);
2750         if (ret)
2751                 return ret;
2752
2753         /* This is safe, since we have a reference from open(). */
2754         __module_get(THIS_MODULE);
2755
2756         pd->bdev = bdev;
2757         set_blocksize(bdev, CD_FRAMESIZE);
2758
2759         pkt_init_queue(pd);
2760
2761         atomic_set(&pd->cdrw.pending_bios, 0);
2762         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2763         if (IS_ERR(pd->cdrw.thread)) {
2764                 printk(DRIVER_NAME": can't start kernel thread\n");
2765                 ret = -ENOMEM;
2766                 goto out_mem;
2767         }
2768
2769         proc = create_proc_entry(pd->name, 0, pkt_proc);
2770         if (proc) {
2771                 proc->data = pd;
2772                 proc->proc_fops = &pkt_proc_fops;
2773         }
2774         DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
2775         return 0;
2776
2777 out_mem:
2778         blkdev_put(bdev);
2779         /* This is safe: open() is still holding a reference. */
2780         module_put(THIS_MODULE);
2781         return ret;
2782 }
2783
2784 static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
2785 {
2786         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2787
2788         VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd, imajor(inode), iminor(inode));
2789
2790         switch (cmd) {
2791         /*
2792          * forward selected CDROM ioctls to CD-ROM, for UDF
2793          */
2794         case CDROMMULTISESSION:
2795         case CDROMREADTOCENTRY:
2796         case CDROM_LAST_WRITTEN:
2797         case CDROM_SEND_PACKET:
2798         case SCSI_IOCTL_SEND_COMMAND:
2799                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2800
2801         case CDROMEJECT:
2802                 /*
2803                  * The door gets locked when the device is opened, so we
2804                  * have to unlock it or else the eject command fails.
2805                  */
2806                 if (pd->refcnt == 1)
2807                         pkt_lock_door(pd, 0);
2808                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2809
2810         default:
2811                 VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, cmd);
2812                 return -ENOTTY;
2813         }
2814
2815         return 0;
2816 }
2817
2818 static int pkt_media_changed(struct gendisk *disk)
2819 {
2820         struct pktcdvd_device *pd = disk->private_data;
2821         struct gendisk *attached_disk;
2822
2823         if (!pd)
2824                 return 0;
2825         if (!pd->bdev)
2826                 return 0;
2827         attached_disk = pd->bdev->bd_disk;
2828         if (!attached_disk)
2829                 return 0;
2830         return attached_disk->fops->media_changed(attached_disk);
2831 }
2832
2833 static struct block_device_operations pktcdvd_ops = {
2834         .owner =                THIS_MODULE,
2835         .open =                 pkt_open,
2836         .release =              pkt_close,
2837         .ioctl =                pkt_ioctl,
2838         .media_changed =        pkt_media_changed,
2839 };
2840
2841 /*
2842  * Set up mapping from pktcdvd device to CD-ROM device.
2843  */
2844 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2845 {
2846         int idx;
2847         int ret = -ENOMEM;
2848         struct pktcdvd_device *pd;
2849         struct gendisk *disk;
2850
2851         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2852
2853         for (idx = 0; idx < MAX_WRITERS; idx++)
2854                 if (!pkt_devs[idx])
2855                         break;
2856         if (idx == MAX_WRITERS) {
2857                 printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
2858                 ret = -EBUSY;
2859                 goto out_mutex;
2860         }
2861
2862         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2863         if (!pd)
2864                 goto out_mutex;
2865
2866         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2867                                                   sizeof(struct pkt_rb_node));
2868         if (!pd->rb_pool)
2869                 goto out_mem;
2870
2871         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2872         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2873         spin_lock_init(&pd->cdrw.active_list_lock);
2874
2875         spin_lock_init(&pd->lock);
2876         spin_lock_init(&pd->iosched.lock);
2877         sprintf(pd->name, DRIVER_NAME"%d", idx);
2878         init_waitqueue_head(&pd->wqueue);
2879         pd->bio_queue = RB_ROOT;
2880
2881         pd->write_congestion_on  = write_congestion_on;
2882         pd->write_congestion_off = write_congestion_off;
2883
2884         disk = alloc_disk(1);
2885         if (!disk)
2886                 goto out_mem;
2887         pd->disk = disk;
2888         disk->major = pktdev_major;
2889         disk->first_minor = idx;
2890         disk->fops = &pktcdvd_ops;
2891         disk->flags = GENHD_FL_REMOVABLE;
2892         strcpy(disk->disk_name, pd->name);
2893         disk->private_data = pd;
2894         disk->queue = blk_alloc_queue(GFP_KERNEL);
2895         if (!disk->queue)
2896                 goto out_mem2;
2897
2898         pd->pkt_dev = MKDEV(disk->major, disk->first_minor);
2899         ret = pkt_new_dev(pd, dev);
2900         if (ret)
2901                 goto out_new_dev;
2902
2903         add_disk(disk);
2904
2905         pkt_sysfs_dev_new(pd);
2906         pkt_debugfs_dev_new(pd);
2907
2908         pkt_devs[idx] = pd;
2909         if (pkt_dev)
2910                 *pkt_dev = pd->pkt_dev;
2911
2912         mutex_unlock(&ctl_mutex);
2913         return 0;
2914
2915 out_new_dev:
2916         blk_cleanup_queue(disk->queue);
2917 out_mem2:
2918         put_disk(disk);
2919 out_mem:
2920         if (pd->rb_pool)
2921                 mempool_destroy(pd->rb_pool);
2922         kfree(pd);
2923 out_mutex:
2924         mutex_unlock(&ctl_mutex);
2925         printk(DRIVER_NAME": setup of pktcdvd device failed\n");
2926         return ret;
2927 }
2928
2929 /*
2930  * Tear down mapping from pktcdvd device to CD-ROM device.
2931  */
2932 static int pkt_remove_dev(dev_t pkt_dev)
2933 {
2934         struct pktcdvd_device *pd;
2935         int idx;
2936         int ret = 0;
2937
2938         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2939
2940         for (idx = 0; idx < MAX_WRITERS; idx++) {
2941                 pd = pkt_devs[idx];
2942                 if (pd && (pd->pkt_dev == pkt_dev))
2943                         break;
2944         }
2945         if (idx == MAX_WRITERS) {
2946                 DPRINTK(DRIVER_NAME": dev not setup\n");
2947                 ret = -ENXIO;
2948                 goto out;
2949         }
2950
2951         if (pd->refcnt > 0) {
2952                 ret = -EBUSY;
2953                 goto out;
2954         }
2955         if (!IS_ERR(pd->cdrw.thread))
2956                 kthread_stop(pd->cdrw.thread);
2957
2958         pkt_devs[idx] = NULL;
2959
2960         pkt_debugfs_dev_remove(pd);
2961         pkt_sysfs_dev_remove(pd);
2962
2963         blkdev_put(pd->bdev);
2964
2965         remove_proc_entry(pd->name, pkt_proc);
2966         DPRINTK(DRIVER_NAME": writer %s unmapped\n", pd->name);
2967
2968         del_gendisk(pd->disk);
2969         blk_cleanup_queue(pd->disk->queue);
2970         put_disk(pd->disk);
2971
2972         mempool_destroy(pd->rb_pool);
2973         kfree(pd);
2974
2975         /* This is safe: open() is still holding a reference. */
2976         module_put(THIS_MODULE);
2977
2978 out:
2979         mutex_unlock(&ctl_mutex);
2980         return ret;
2981 }
2982
2983 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2984 {
2985         struct pktcdvd_device *pd;
2986
2987         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2988
2989         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2990         if (pd) {
2991                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2992                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2993         } else {
2994                 ctrl_cmd->dev = 0;
2995                 ctrl_cmd->pkt_dev = 0;
2996         }
2997         ctrl_cmd->num_devices = MAX_WRITERS;
2998
2999         mutex_unlock(&ctl_mutex);
3000 }
3001
3002 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
3003 {
3004         void __user *argp = (void __user *)arg;
3005         struct pkt_ctrl_command ctrl_cmd;
3006         int ret = 0;
3007         dev_t pkt_dev = 0;
3008
3009         if (cmd != PACKET_CTRL_CMD)
3010                 return -ENOTTY;
3011
3012         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
3013                 return -EFAULT;
3014
3015         switch (ctrl_cmd.command) {
3016         case PKT_CTRL_CMD_SETUP:
3017                 if (!capable(CAP_SYS_ADMIN))
3018                         return -EPERM;
3019                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
3020                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
3021                 break;
3022         case PKT_CTRL_CMD_TEARDOWN:
3023                 if (!capable(CAP_SYS_ADMIN))
3024                         return -EPERM;
3025                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
3026                 break;
3027         case PKT_CTRL_CMD_STATUS:
3028                 pkt_get_status(&ctrl_cmd);
3029                 break;
3030         default:
3031                 return -ENOTTY;
3032         }
3033
3034         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
3035                 return -EFAULT;
3036         return ret;
3037 }
3038
3039
3040 static const struct file_operations pkt_ctl_fops = {
3041         .ioctl   = pkt_ctl_ioctl,
3042         .owner   = THIS_MODULE,
3043 };
3044
3045 static struct miscdevice pkt_misc = {
3046         .minor          = MISC_DYNAMIC_MINOR,
3047         .name           = DRIVER_NAME,
3048         .fops           = &pkt_ctl_fops
3049 };
3050
3051 static int __init pkt_init(void)
3052 {
3053         int ret;
3054
3055         mutex_init(&ctl_mutex);
3056
3057         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
3058                                         sizeof(struct packet_stacked_data));
3059         if (!psd_pool)
3060                 return -ENOMEM;
3061
3062         ret = register_blkdev(pktdev_major, DRIVER_NAME);
3063         if (ret < 0) {
3064                 printk(DRIVER_NAME": Unable to register block device\n");
3065                 goto out2;
3066         }
3067         if (!pktdev_major)
3068                 pktdev_major = ret;
3069
3070         ret = pkt_sysfs_init();
3071         if (ret)
3072                 goto out;
3073
3074         pkt_debugfs_init();
3075
3076         ret = misc_register(&pkt_misc);
3077         if (ret) {
3078                 printk(DRIVER_NAME": Unable to register misc device\n");
3079                 goto out_misc;
3080         }
3081
3082         pkt_proc = proc_mkdir(DRIVER_NAME, proc_root_driver);
3083
3084         return 0;
3085
3086 out_misc:
3087         pkt_debugfs_cleanup();
3088         pkt_sysfs_cleanup();
3089 out:
3090         unregister_blkdev(pktdev_major, DRIVER_NAME);
3091 out2:
3092         mempool_destroy(psd_pool);
3093         return ret;
3094 }
3095
3096 static void __exit pkt_exit(void)
3097 {
3098         remove_proc_entry(DRIVER_NAME, proc_root_driver);
3099         misc_deregister(&pkt_misc);
3100
3101         pkt_debugfs_cleanup();
3102         pkt_sysfs_cleanup();
3103
3104         unregister_blkdev(pktdev_major, DRIVER_NAME);
3105         mempool_destroy(psd_pool);
3106 }
3107
3108 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3109 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3110 MODULE_LICENSE("GPL");
3111
3112 module_init(pkt_init);
3113 module_exit(pkt_exit);