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

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   4  * 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         int error;
 114
 115         p = kzalloc(sizeof(*p), GFP_KERNEL);
 116         if (!p)
 117                 return NULL;
 118         p->pd = pd;
 119         error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
 120         if (error) {
 121                 kobject_put(&p->kobj);
 122                 return NULL;
 123         }
 124         kobject_uevent(&p->kobj, KOBJ_ADD);
 125         return p;
 126 }
 127 /*
 128  * remove a pktcdvd kernel object.
 129  */
 130 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
 131 {
 132         if (p)
 133                 kobject_put(&p->kobj);
 134 }
 135 /*
 136  * default release function for pktcdvd kernel objects.
 137  */
 138 static void pkt_kobj_release(struct kobject *kobj)
 139 {
 140         kfree(to_pktcdvdkobj(kobj));
 141 }
 142
 143
 144 /**********************************************************
 145  *
 146  * sysfs interface for pktcdvd
 147  * by (C) 2006  Thomas Maier <balagi@justmail.de>
 148  *
 149  **********************************************************/
 150
 151 #define DEF_ATTR(_obj,_name,_mode) \
 152         static struct attribute _obj = { .name = _name, .mode = _mode }
 153
 154 /**********************************************************
 155   /sys/class/pktcdvd/pktcdvd[0-7]/
 156                      stat/reset
 157                      stat/packets_started
 158                      stat/packets_finished
 159                      stat/kb_written
 160                      stat/kb_read
 161                      stat/kb_read_gather
 162                      write_queue/size
 163                      write_queue/congestion_off
 164                      write_queue/congestion_on
 165  **********************************************************/
 166
 167 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
 168 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
 169 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
 170 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
 171 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
 172 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
 173
 174 static struct attribute *kobj_pkt_attrs_stat[] = {
 175         &kobj_pkt_attr_st1,
 176         &kobj_pkt_attr_st2,
 177         &kobj_pkt_attr_st3,
 178         &kobj_pkt_attr_st4,
 179         &kobj_pkt_attr_st5,
 180         &kobj_pkt_attr_st6,
 181         NULL
 182 };
 183
 184 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
 185 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
 186 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
 187
 188 static struct attribute *kobj_pkt_attrs_wqueue[] = {
 189         &kobj_pkt_attr_wq1,
 190         &kobj_pkt_attr_wq2,
 191         &kobj_pkt_attr_wq3,
 192         NULL
 193 };
 194
 195 static ssize_t kobj_pkt_show(struct kobject *kobj,
 196                         struct attribute *attr, char *data)
 197 {
 198         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 199         int n = 0;
 200         int v;
 201         if (strcmp(attr->name, "packets_started") == 0) {
 202                 n = sprintf(data, "%lu\n", pd->stats.pkt_started);
 203
 204         } else if (strcmp(attr->name, "packets_finished") == 0) {
 205                 n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
 206
 207         } else if (strcmp(attr->name, "kb_written") == 0) {
 208                 n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
 209
 210         } else if (strcmp(attr->name, "kb_read") == 0) {
 211                 n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
 212
 213         } else if (strcmp(attr->name, "kb_read_gather") == 0) {
 214                 n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
 215
 216         } else if (strcmp(attr->name, "size") == 0) {
 217                 spin_lock(&pd->lock);
 218                 v = pd->bio_queue_size;
 219                 spin_unlock(&pd->lock);
 220                 n = sprintf(data, "%d\n", v);
 221
 222         } else if (strcmp(attr->name, "congestion_off") == 0) {
 223                 spin_lock(&pd->lock);
 224                 v = pd->write_congestion_off;
 225                 spin_unlock(&pd->lock);
 226                 n = sprintf(data, "%d\n", v);
 227
 228         } else if (strcmp(attr->name, "congestion_on") == 0) {
 229                 spin_lock(&pd->lock);
 230                 v = pd->write_congestion_on;
 231                 spin_unlock(&pd->lock);
 232                 n = sprintf(data, "%d\n", v);
 233         }
 234         return n;
 235 }
 236
 237 static void init_write_congestion_marks(int* lo, int* hi)
 238 {
 239         if (*hi > 0) {
 240                 *hi = max(*hi, 500);
 241                 *hi = min(*hi, 1000000);
 242                 if (*lo <= 0)
 243                         *lo = *hi - 100;
 244                 else {
 245                         *lo = min(*lo, *hi - 100);
 246                         *lo = max(*lo, 100);
 247                 }
 248         } else {
 249                 *hi = -1;
 250                 *lo = -1;
 251         }
 252 }
 253
 254 static ssize_t kobj_pkt_store(struct kobject *kobj,
 255                         struct attribute *attr,
 256                         const char *data, size_t len)
 257 {
 258         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 259         int val;
 260
 261         if (strcmp(attr->name, "reset") == 0 && len > 0) {
 262                 pd->stats.pkt_started = 0;
 263                 pd->stats.pkt_ended = 0;
 264                 pd->stats.secs_w = 0;
 265                 pd->stats.secs_rg = 0;
 266                 pd->stats.secs_r = 0;
 267
 268         } else if (strcmp(attr->name, "congestion_off") == 0
 269                    && sscanf(data, "%d", &val) == 1) {
 270                 spin_lock(&pd->lock);
 271                 pd->write_congestion_off = val;
 272                 init_write_congestion_marks(&pd->write_congestion_off,
 273                                         &pd->write_congestion_on);
 274                 spin_unlock(&pd->lock);
 275
 276         } else if (strcmp(attr->name, "congestion_on") == 0
 277                    && sscanf(data, "%d", &val) == 1) {
 278                 spin_lock(&pd->lock);
 279                 pd->write_congestion_on = val;
 280                 init_write_congestion_marks(&pd->write_congestion_off,
 281                                         &pd->write_congestion_on);
 282                 spin_unlock(&pd->lock);
 283         }
 284         return len;
 285 }
 286
 287 static struct sysfs_ops kobj_pkt_ops = {
 288         .show = kobj_pkt_show,
 289         .store = kobj_pkt_store
 290 };
 291 static struct kobj_type kobj_pkt_type_stat = {
 292         .release = pkt_kobj_release,
 293         .sysfs_ops = &kobj_pkt_ops,
 294         .default_attrs = kobj_pkt_attrs_stat
 295 };
 296 static struct kobj_type kobj_pkt_type_wqueue = {
 297         .release = pkt_kobj_release,
 298         .sysfs_ops = &kobj_pkt_ops,
 299         .default_attrs = kobj_pkt_attrs_wqueue
 300 };
 301
 302 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 303 {
 304         if (class_pktcdvd) {
 305                 pd->dev = device_create(class_pktcdvd, NULL, pd->pkt_dev, "%s", pd->name);
 306                 if (IS_ERR(pd->dev))
 307                         pd->dev = NULL;
 308         }
 309         if (pd->dev) {
 310                 pd->kobj_stat = pkt_kobj_create(pd, "stat",
 311                                         &pd->dev->kobj,
 312                                         &kobj_pkt_type_stat);
 313                 pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
 314                                         &pd->dev->kobj,
 315                                         &kobj_pkt_type_wqueue);
 316         }
 317 }
 318
 319 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 320 {
 321         pkt_kobj_remove(pd->kobj_stat);
 322         pkt_kobj_remove(pd->kobj_wqueue);
 323         if (class_pktcdvd)
 324                 device_destroy(class_pktcdvd, pd->pkt_dev);
 325 }
 326
 327
 328 /********************************************************************
 329   /sys/class/pktcdvd/
 330                      add            map block device
 331                      remove         unmap packet dev
 332                      device_map     show mappings
 333  *******************************************************************/
 334
 335 static void class_pktcdvd_release(struct class *cls)
 336 {
 337         kfree(cls);
 338 }
 339 static ssize_t class_pktcdvd_show_map(struct class *c, char *data)
 340 {
 341         int n = 0;
 342         int idx;
 343         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 344         for (idx = 0; idx < MAX_WRITERS; idx++) {
 345                 struct pktcdvd_device *pd = pkt_devs[idx];
 346                 if (!pd)
 347                         continue;
 348                 n += sprintf(data+n, "%s %u:%u %u:%u\n",
 349                         pd->name,
 350                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 351                         MAJOR(pd->bdev->bd_dev),
 352                         MINOR(pd->bdev->bd_dev));
 353         }
 354         mutex_unlock(&ctl_mutex);
 355         return n;
 356 }
 357
 358 static ssize_t class_pktcdvd_store_add(struct class *c, const char *buf,
 359                                         size_t count)
 360 {
 361         unsigned int major, minor;
 362
 363         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 364                 /* pkt_setup_dev() expects caller to hold reference to self */
 365                 if (!try_module_get(THIS_MODULE))
 366                         return -ENODEV;
 367
 368                 pkt_setup_dev(MKDEV(major, minor), NULL);
 369
 370                 module_put(THIS_MODULE);
 371
 372                 return count;
 373         }
 374
 375         return -EINVAL;
 376 }
 377
 378 static ssize_t class_pktcdvd_store_remove(struct class *c, const char *buf,
 379                                         size_t count)
 380 {
 381         unsigned int major, minor;
 382         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 383                 pkt_remove_dev(MKDEV(major, minor));
 384                 return count;
 385         }
 386         return -EINVAL;
 387 }
 388
 389 static struct class_attribute class_pktcdvd_attrs[] = {
 390  __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
 391  __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
 392  __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
 393  __ATTR_NULL
 394 };
 395
 396
 397 static int pkt_sysfs_init(void)
 398 {
 399         int ret = 0;
 400
 401         /*
 402          * create control files in sysfs
 403          * /sys/class/pktcdvd/...
 404          */
 405         class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
 406         if (!class_pktcdvd)
 407                 return -ENOMEM;
 408         class_pktcdvd->name = DRIVER_NAME;
 409         class_pktcdvd->owner = THIS_MODULE;
 410         class_pktcdvd->class_release = class_pktcdvd_release;
 411         class_pktcdvd->class_attrs = class_pktcdvd_attrs;
 412         ret = class_register(class_pktcdvd);
 413         if (ret) {
 414                 kfree(class_pktcdvd);
 415                 class_pktcdvd = NULL;
 416                 printk(DRIVER_NAME": failed to create class pktcdvd\n");
 417                 return ret;
 418         }
 419         return 0;
 420 }
 421
 422 static void pkt_sysfs_cleanup(void)
 423 {
 424         if (class_pktcdvd)
 425                 class_destroy(class_pktcdvd);
 426         class_pktcdvd = NULL;
 427 }
 428
 429 /********************************************************************
 430   entries in debugfs
 431
 432   /debugfs/pktcdvd[0-7]/
 433                         info
 434
 435  *******************************************************************/
 436
 437 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
 438 {
 439         return pkt_seq_show(m, p);
 440 }
 441
 442 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
 443 {
 444         return single_open(file, pkt_debugfs_seq_show, inode->i_private);
 445 }
 446
 447 static const struct file_operations debug_fops = {
 448         .open           = pkt_debugfs_fops_open,
 449         .read           = seq_read,
 450         .llseek         = seq_lseek,
 451         .release        = single_release,
 452         .owner          = THIS_MODULE,
 453 };
 454
 455 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 456 {
 457         if (!pkt_debugfs_root)
 458                 return;
 459         pd->dfs_f_info = NULL;
 460         pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
 461         if (IS_ERR(pd->dfs_d_root)) {
 462                 pd->dfs_d_root = NULL;
 463                 return;
 464         }
 465         pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
 466                                 pd->dfs_d_root, pd, &debug_fops);
 467         if (IS_ERR(pd->dfs_f_info)) {
 468                 pd->dfs_f_info = NULL;
 469                 return;
 470         }
 471 }
 472
 473 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
 474 {
 475         if (!pkt_debugfs_root)
 476                 return;
 477         if (pd->dfs_f_info)
 478                 debugfs_remove(pd->dfs_f_info);
 479         pd->dfs_f_info = NULL;
 480         if (pd->dfs_d_root)
 481                 debugfs_remove(pd->dfs_d_root);
 482         pd->dfs_d_root = NULL;
 483 }
 484
 485 static void pkt_debugfs_init(void)
 486 {
 487         pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
 488         if (IS_ERR(pkt_debugfs_root)) {
 489                 pkt_debugfs_root = NULL;
 490                 return;
 491         }
 492 }
 493
 494 static void pkt_debugfs_cleanup(void)
 495 {
 496         if (!pkt_debugfs_root)
 497                 return;
 498         debugfs_remove(pkt_debugfs_root);
 499         pkt_debugfs_root = NULL;
 500 }
 501
 502 /* ----------------------------------------------------------*/
 503
 504
 505 static void pkt_bio_finished(struct pktcdvd_device *pd)
 506 {
 507         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
 508         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
 509                 VPRINTK(DRIVER_NAME": queue empty\n");
 510                 atomic_set(&pd->iosched.attention, 1);
 511                 wake_up(&pd->wqueue);
 512         }
 513 }
 514
 515 static void pkt_bio_destructor(struct bio *bio)
 516 {
 517         kfree(bio->bi_io_vec);
 518         kfree(bio);
 519 }
 520
 521 static struct bio *pkt_bio_alloc(int nr_iovecs)
 522 {
 523         struct bio_vec *bvl = NULL;
 524         struct bio *bio;
 525
 526         bio = kmalloc(sizeof(struct bio), GFP_KERNEL);
 527         if (!bio)
 528                 goto no_bio;
 529         bio_init(bio);
 530
 531         bvl = kcalloc(nr_iovecs, sizeof(struct bio_vec), GFP_KERNEL);
 532         if (!bvl)
 533                 goto no_bvl;
 534
 535         bio->bi_max_vecs = nr_iovecs;
 536         bio->bi_io_vec = bvl;
 537         bio->bi_destructor = pkt_bio_destructor;
 538
 539         return bio;
 540
 541  no_bvl:
 542         kfree(bio);
 543  no_bio:
 544         return NULL;
 545 }
 546
 547 /*
 548  * Allocate a packet_data struct
 549  */
 550 static struct packet_data *pkt_alloc_packet_data(int frames)
 551 {
 552         int i;
 553         struct packet_data *pkt;
 554
 555         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 556         if (!pkt)
 557                 goto no_pkt;
 558
 559         pkt->frames = frames;
 560         pkt->w_bio = pkt_bio_alloc(frames);
 561         if (!pkt->w_bio)
 562                 goto no_bio;
 563
 564         for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 565                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 566                 if (!pkt->pages[i])
 567                         goto no_page;
 568         }
 569
 570         spin_lock_init(&pkt->lock);
 571
 572         for (i = 0; i < frames; i++) {
 573                 struct bio *bio = pkt_bio_alloc(1);
 574                 if (!bio)
 575                         goto no_rd_bio;
 576                 pkt->r_bios[i] = bio;
 577         }
 578
 579         return pkt;
 580
 581 no_rd_bio:
 582         for (i = 0; i < frames; i++) {
 583                 struct bio *bio = pkt->r_bios[i];
 584                 if (bio)
 585                         bio_put(bio);
 586         }
 587
 588 no_page:
 589         for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 590                 if (pkt->pages[i])
 591                         __free_page(pkt->pages[i]);
 592         bio_put(pkt->w_bio);
 593 no_bio:
 594         kfree(pkt);
 595 no_pkt:
 596         return NULL;
 597 }
 598
 599 /*
 600  * Free a packet_data struct
 601  */
 602 static void pkt_free_packet_data(struct packet_data *pkt)
 603 {
 604         int i;
 605
 606         for (i = 0; i < pkt->frames; i++) {
 607                 struct bio *bio = pkt->r_bios[i];
 608                 if (bio)
 609                         bio_put(bio);
 610         }
 611         for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 612                 __free_page(pkt->pages[i]);
 613         bio_put(pkt->w_bio);
 614         kfree(pkt);
 615 }
 616
 617 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 618 {
 619         struct packet_data *pkt, *next;
 620
 621         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 622
 623         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 624                 pkt_free_packet_data(pkt);
 625         }
 626         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 627 }
 628
 629 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 630 {
 631         struct packet_data *pkt;
 632
 633         BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
 634
 635         while (nr_packets > 0) {
 636                 pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 637                 if (!pkt) {
 638                         pkt_shrink_pktlist(pd);
 639                         return 0;
 640                 }
 641                 pkt->id = nr_packets;
 642                 pkt->pd = pd;
 643                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 644                 nr_packets--;
 645         }
 646         return 1;
 647 }
 648
 649 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 650 {
 651         struct rb_node *n = rb_next(&node->rb_node);
 652         if (!n)
 653                 return NULL;
 654         return rb_entry(n, struct pkt_rb_node, rb_node);
 655 }
 656
 657 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 658 {
 659         rb_erase(&node->rb_node, &pd->bio_queue);
 660         mempool_free(node, pd->rb_pool);
 661         pd->bio_queue_size--;
 662         BUG_ON(pd->bio_queue_size < 0);
 663 }
 664
 665 /*
 666  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 667  */
 668 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 669 {
 670         struct rb_node *n = pd->bio_queue.rb_node;
 671         struct rb_node *next;
 672         struct pkt_rb_node *tmp;
 673
 674         if (!n) {
 675                 BUG_ON(pd->bio_queue_size > 0);
 676                 return NULL;
 677         }
 678
 679         for (;;) {
 680                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 681                 if (s <= tmp->bio->bi_sector)
 682                         next = n->rb_left;
 683                 else
 684                         next = n->rb_right;
 685                 if (!next)
 686                         break;
 687                 n = next;
 688         }
 689
 690         if (s > tmp->bio->bi_sector) {
 691                 tmp = pkt_rbtree_next(tmp);
 692                 if (!tmp)
 693                         return NULL;
 694         }
 695         BUG_ON(s > tmp->bio->bi_sector);
 696         return tmp;
 697 }
 698
 699 /*
 700  * Insert a node into the pd->bio_queue rb tree.
 701  */
 702 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 703 {
 704         struct rb_node **p = &pd->bio_queue.rb_node;
 705         struct rb_node *parent = NULL;
 706         sector_t s = node->bio->bi_sector;
 707         struct pkt_rb_node *tmp;
 708
 709         while (*p) {
 710                 parent = *p;
 711                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 712                 if (s < tmp->bio->bi_sector)
 713                         p = &(*p)->rb_left;
 714                 else
 715                         p = &(*p)->rb_right;
 716         }
 717         rb_link_node(&node->rb_node, parent, p);
 718         rb_insert_color(&node->rb_node, &pd->bio_queue);
 719         pd->bio_queue_size++;
 720 }
 721
 722 /*
 723  * Add a bio to a single linked list defined by its head and tail pointers.
 724  */
 725 static void pkt_add_list_last(struct bio *bio, struct bio **list_head, struct bio **list_tail)
 726 {
 727         bio->bi_next = NULL;
 728         if (*list_tail) {
 729                 BUG_ON((*list_head) == NULL);
 730                 (*list_tail)->bi_next = bio;
 731                 (*list_tail) = bio;
 732         } else {
 733                 BUG_ON((*list_head) != NULL);
 734                 (*list_head) = bio;
 735                 (*list_tail) = bio;
 736         }
 737 }
 738
 739 /*
 740  * Remove and return the first bio from a single linked list defined by its
 741  * head and tail pointers.
 742  */
 743 static inline struct bio *pkt_get_list_first(struct bio **list_head, struct bio **list_tail)
 744 {
 745         struct bio *bio;
 746
 747         if (*list_head == NULL)
 748                 return NULL;
 749
 750         bio = *list_head;
 751         *list_head = bio->bi_next;
 752         if (*list_head == NULL)
 753                 *list_tail = NULL;
 754
 755         bio->bi_next = NULL;
 756         return bio;
 757 }
 758
 759 /*
 760  * Send a packet_command to the underlying block device and
 761  * wait for completion.
 762  */
 763 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 764 {
 765         struct request_queue *q = bdev_get_queue(pd->bdev);
 766         struct request *rq;
 767         int ret = 0;
 768
 769         rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 770                              WRITE : READ, __GFP_WAIT);
 771
 772         if (cgc->buflen) {
 773                 if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
 774                         goto out;
 775         }
 776
 777         rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 778         memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 779         if (sizeof(rq->cmd) > CDROM_PACKET_SIZE)
 780                 memset(rq->cmd + CDROM_PACKET_SIZE, 0, sizeof(rq->cmd) - CDROM_PACKET_SIZE);
 781
 782         rq->timeout = 60*HZ;
 783         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 784         rq->cmd_flags |= REQ_HARDBARRIER;
 785         if (cgc->quiet)
 786                 rq->cmd_flags |= REQ_QUIET;
 787
 788         blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
 789         if (rq->errors)
 790                 ret = -EIO;
 791 out:
 792         blk_put_request(rq);
 793         return ret;
 794 }
 795
 796 /*
 797  * A generic sense dump / resolve mechanism should be implemented across
 798  * all ATAPI + SCSI devices.
 799  */
 800 static void pkt_dump_sense(struct packet_command *cgc)
 801 {
 802         static char *info[9] = { "No sense", "Recovered error", "Not ready",
 803                                  "Medium error", "Hardware error", "Illegal request",
 804                                  "Unit attention", "Data protect", "Blank check" };
 805         int i;
 806         struct request_sense *sense = cgc->sense;
 807
 808         printk(DRIVER_NAME":");
 809         for (i = 0; i < CDROM_PACKET_SIZE; i++)
 810                 printk(" %02x", cgc->cmd[i]);
 811         printk(" - ");
 812
 813         if (sense == NULL) {
 814                 printk("no sense\n");
 815                 return;
 816         }
 817
 818         printk("sense %02x.%02x.%02x", sense->sense_key, sense->asc, sense->ascq);
 819
 820         if (sense->sense_key > 8) {
 821                 printk(" (INVALID)\n");
 822                 return;
 823         }
 824
 825         printk(" (%s)\n", info[sense->sense_key]);
 826 }
 827
 828 /*
 829  * flush the drive cache to media
 830  */
 831 static int pkt_flush_cache(struct pktcdvd_device *pd)
 832 {
 833         struct packet_command cgc;
 834
 835         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 836         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 837         cgc.quiet = 1;
 838
 839         /*
 840          * the IMMED bit -- we default to not setting it, although that
 841          * would allow a much faster close, this is safer
 842          */
 843 #if 0
 844         cgc.cmd[1] = 1 << 1;
 845 #endif
 846         return pkt_generic_packet(pd, &cgc);
 847 }
 848
 849 /*
 850  * speed is given as the normal factor, e.g. 4 for 4x
 851  */
 852 static int pkt_set_speed(struct pktcdvd_device *pd, unsigned write_speed, unsigned read_speed)
 853 {
 854         struct packet_command cgc;
 855         struct request_sense sense;
 856         int ret;
 857
 858         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 859         cgc.sense = &sense;
 860         cgc.cmd[0] = GPCMD_SET_SPEED;
 861         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 862         cgc.cmd[3] = read_speed & 0xff;
 863         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 864         cgc.cmd[5] = write_speed & 0xff;
 865
 866         if ((ret = pkt_generic_packet(pd, &cgc)))
 867                 pkt_dump_sense(&cgc);
 868
 869         return ret;
 870 }
 871
 872 /*
 873  * Queue a bio for processing by the low-level CD device. Must be called
 874  * from process context.
 875  */
 876 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 877 {
 878         spin_lock(&pd->iosched.lock);
 879         if (bio_data_dir(bio) == READ) {
 880                 pkt_add_list_last(bio, &pd->iosched.read_queue,
 881                                   &pd->iosched.read_queue_tail);
 882         } else {
 883                 pkt_add_list_last(bio, &pd->iosched.write_queue,
 884                                   &pd->iosched.write_queue_tail);
 885         }
 886         spin_unlock(&pd->iosched.lock);
 887
 888         atomic_set(&pd->iosched.attention, 1);
 889         wake_up(&pd->wqueue);
 890 }
 891
 892 /*
 893  * Process the queued read/write requests. This function handles special
 894  * requirements for CDRW drives:
 895  * - A cache flush command must be inserted before a read request if the
 896  *   previous request was a write.
 897  * - Switching between reading and writing is slow, so don't do it more often
 898  *   than necessary.
 899  * - Optimize for throughput at the expense of latency. This means that streaming
 900  *   writes will never be interrupted by a read, but if the drive has to seek
 901  *   before the next write, switch to reading instead if there are any pending
 902  *   read requests.
 903  * - Set the read speed according to current usage pattern. When only reading
 904  *   from the device, it's best to use the highest possible read speed, but
 905  *   when switching often between reading and writing, it's better to have the
 906  *   same read and write speeds.
 907  */
 908 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 909 {
 910
 911         if (atomic_read(&pd->iosched.attention) == 0)
 912                 return;
 913         atomic_set(&pd->iosched.attention, 0);
 914
 915         for (;;) {
 916                 struct bio *bio;
 917                 int reads_queued, writes_queued;
 918
 919                 spin_lock(&pd->iosched.lock);
 920                 reads_queued = (pd->iosched.read_queue != NULL);
 921                 writes_queued = (pd->iosched.write_queue != NULL);
 922                 spin_unlock(&pd->iosched.lock);
 923
 924                 if (!reads_queued && !writes_queued)
 925                         break;
 926
 927                 if (pd->iosched.writing) {
 928                         int need_write_seek = 1;
 929                         spin_lock(&pd->iosched.lock);
 930                         bio = pd->iosched.write_queue;
 931                         spin_unlock(&pd->iosched.lock);
 932                         if (bio && (bio->bi_sector == pd->iosched.last_write))
 933                                 need_write_seek = 0;
 934                         if (need_write_seek && reads_queued) {
 935                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 936                                         VPRINTK(DRIVER_NAME": write, waiting\n");
 937                                         break;
 938                                 }
 939                                 pkt_flush_cache(pd);
 940                                 pd->iosched.writing = 0;
 941                         }
 942                 } else {
 943                         if (!reads_queued && writes_queued) {
 944                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 945                                         VPRINTK(DRIVER_NAME": read, waiting\n");
 946                                         break;
 947                                 }
 948                                 pd->iosched.writing = 1;
 949                         }
 950                 }
 951
 952                 spin_lock(&pd->iosched.lock);
 953                 if (pd->iosched.writing) {
 954                         bio = pkt_get_list_first(&pd->iosched.write_queue,
 955                                                  &pd->iosched.write_queue_tail);
 956                 } else {
 957                         bio = pkt_get_list_first(&pd->iosched.read_queue,
 958                                                  &pd->iosched.read_queue_tail);
 959                 }
 960                 spin_unlock(&pd->iosched.lock);
 961
 962                 if (!bio)
 963                         continue;
 964
 965                 if (bio_data_dir(bio) == READ)
 966                         pd->iosched.successive_reads += bio->bi_size >> 10;
 967                 else {
 968                         pd->iosched.successive_reads = 0;
 969                         pd->iosched.last_write = bio->bi_sector + bio_sectors(bio);
 970                 }
 971                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 972                         if (pd->read_speed == pd->write_speed) {
 973                                 pd->read_speed = MAX_SPEED;
 974                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 975                         }
 976                 } else {
 977                         if (pd->read_speed != pd->write_speed) {
 978                                 pd->read_speed = pd->write_speed;
 979                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 980                         }
 981                 }
 982
 983                 atomic_inc(&pd->cdrw.pending_bios);
 984                 generic_make_request(bio);
 985         }
 986 }
 987
 988 /*
 989  * Special care is needed if the underlying block device has a small
 990  * max_phys_segments value.
 991  */
 992 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 993 {
 994         if ((pd->settings.size << 9) / CD_FRAMESIZE <= q->max_phys_segments) {
 995                 /*
 996                  * The cdrom device can handle one segment/frame
 997                  */
 998                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 999                 return 0;
1000         } else if ((pd->settings.size << 9) / PAGE_SIZE <= q->max_phys_segments) {
1001                 /*
1002                  * We can handle this case at the expense of some extra memory
1003                  * copies during write operations
1004                  */
1005                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
1006                 return 0;
1007         } else {
1008                 printk(DRIVER_NAME": cdrom max_phys_segments too small\n");
1009                 return -EIO;
1010         }
1011 }
1012
1013 /*
1014  * Copy CD_FRAMESIZE bytes from src_bio into a destination page
1015  */
1016 static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
1017 {
1018         unsigned int copy_size = CD_FRAMESIZE;
1019
1020         while (copy_size > 0) {
1021                 struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
1022                 void *vfrom = kmap_atomic(src_bvl->bv_page, KM_USER0) +
1023                         src_bvl->bv_offset + offs;
1024                 void *vto = page_address(dst_page) + dst_offs;
1025                 int len = min_t(int, copy_size, src_bvl->bv_len - offs);
1026
1027                 BUG_ON(len < 0);
1028                 memcpy(vto, vfrom, len);
1029                 kunmap_atomic(vfrom, KM_USER0);
1030
1031                 seg++;
1032                 offs = 0;
1033                 dst_offs += len;
1034                 copy_size -= len;
1035         }
1036 }
1037
1038 /*
1039  * Copy all data for this packet to pkt->pages[], so that
1040  * a) The number of required segments for the write bio is minimized, which
1041  *    is necessary for some scsi controllers.
1042  * b) The data can be used as cache to avoid read requests if we receive a
1043  *    new write request for the same zone.
1044  */
1045 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
1046 {
1047         int f, p, offs;
1048
1049         /* Copy all data to pkt->pages[] */
1050         p = 0;
1051         offs = 0;
1052         for (f = 0; f < pkt->frames; f++) {
1053                 if (bvec[f].bv_page != pkt->pages[p]) {
1054                         void *vfrom = kmap_atomic(bvec[f].bv_page, KM_USER0) + bvec[f].bv_offset;
1055                         void *vto = page_address(pkt->pages[p]) + offs;
1056                         memcpy(vto, vfrom, CD_FRAMESIZE);
1057                         kunmap_atomic(vfrom, KM_USER0);
1058                         bvec[f].bv_page = pkt->pages[p];
1059                         bvec[f].bv_offset = offs;
1060                 } else {
1061                         BUG_ON(bvec[f].bv_offset != offs);
1062                 }
1063                 offs += CD_FRAMESIZE;
1064                 if (offs >= PAGE_SIZE) {
1065                         offs = 0;
1066                         p++;
1067                 }
1068         }
1069 }
1070
1071 static void pkt_end_io_read(struct bio *bio, int err)
1072 {
1073         struct packet_data *pkt = bio->bi_private;
1074         struct pktcdvd_device *pd = pkt->pd;
1075         BUG_ON(!pd);
1076
1077         VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
1078                 (unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
1079
1080         if (err)
1081                 atomic_inc(&pkt->io_errors);
1082         if (atomic_dec_and_test(&pkt->io_wait)) {
1083                 atomic_inc(&pkt->run_sm);
1084                 wake_up(&pd->wqueue);
1085         }
1086         pkt_bio_finished(pd);
1087 }
1088
1089 static void pkt_end_io_packet_write(struct bio *bio, int err)
1090 {
1091         struct packet_data *pkt = bio->bi_private;
1092         struct pktcdvd_device *pd = pkt->pd;
1093         BUG_ON(!pd);
1094
1095         VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
1096
1097         pd->stats.pkt_ended++;
1098
1099         pkt_bio_finished(pd);
1100         atomic_dec(&pkt->io_wait);
1101         atomic_inc(&pkt->run_sm);
1102         wake_up(&pd->wqueue);
1103 }
1104
1105 /*
1106  * Schedule reads for the holes in a packet
1107  */
1108 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1109 {
1110         int frames_read = 0;
1111         struct bio *bio;
1112         int f;
1113         char written[PACKET_MAX_SIZE];
1114
1115         BUG_ON(!pkt->orig_bios);
1116
1117         atomic_set(&pkt->io_wait, 0);
1118         atomic_set(&pkt->io_errors, 0);
1119
1120         /*
1121          * Figure out which frames we need to read before we can write.
1122          */
1123         memset(written, 0, sizeof(written));
1124         spin_lock(&pkt->lock);
1125         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1126                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1127                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1128                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1129                 BUG_ON(first_frame < 0);
1130                 BUG_ON(first_frame + num_frames > pkt->frames);
1131                 for (f = first_frame; f < first_frame + num_frames; f++)
1132                         written[f] = 1;
1133         }
1134         spin_unlock(&pkt->lock);
1135
1136         if (pkt->cache_valid) {
1137                 VPRINTK("pkt_gather_data: zone %llx cached\n",
1138                         (unsigned long long)pkt->sector);
1139                 goto out_account;
1140         }
1141
1142         /*
1143          * Schedule reads for missing parts of the packet.
1144          */
1145         for (f = 0; f < pkt->frames; f++) {
1146                 struct bio_vec *vec;
1147
1148                 int p, offset;
1149                 if (written[f])
1150                         continue;
1151                 bio = pkt->r_bios[f];
1152                 vec = bio->bi_io_vec;
1153                 bio_init(bio);
1154                 bio->bi_max_vecs = 1;
1155                 bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1156                 bio->bi_bdev = pd->bdev;
1157                 bio->bi_end_io = pkt_end_io_read;
1158                 bio->bi_private = pkt;
1159                 bio->bi_io_vec = vec;
1160                 bio->bi_destructor = pkt_bio_destructor;
1161
1162                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1163                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1164                 VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
1165                         f, pkt->pages[p], offset);
1166                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1167                         BUG();
1168
1169                 atomic_inc(&pkt->io_wait);
1170                 bio->bi_rw = READ;
1171                 pkt_queue_bio(pd, bio);
1172                 frames_read++;
1173         }
1174
1175 out_account:
1176         VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
1177                 frames_read, (unsigned long long)pkt->sector);
1178         pd->stats.pkt_started++;
1179         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1180 }
1181
1182 /*
1183  * Find a packet matching zone, or the least recently used packet if
1184  * there is no match.
1185  */
1186 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1187 {
1188         struct packet_data *pkt;
1189
1190         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1191                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1192                         list_del_init(&pkt->list);
1193                         if (pkt->sector != zone)
1194                                 pkt->cache_valid = 0;
1195                         return pkt;
1196                 }
1197         }
1198         BUG();
1199         return NULL;
1200 }
1201
1202 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1203 {
1204         if (pkt->cache_valid) {
1205                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1206         } else {
1207                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1208         }
1209 }
1210
1211 /*
1212  * recover a failed write, query for relocation if possible
1213  *
1214  * returns 1 if recovery is possible, or 0 if not
1215  *
1216  */
1217 static int pkt_start_recovery(struct packet_data *pkt)
1218 {
1219         /*
1220          * FIXME. We need help from the file system to implement
1221          * recovery handling.
1222          */
1223         return 0;
1224 #if 0
1225         struct request *rq = pkt->rq;
1226         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1227         struct block_device *pkt_bdev;
1228         struct super_block *sb = NULL;
1229         unsigned long old_block, new_block;
1230         sector_t new_sector;
1231
1232         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1233         if (pkt_bdev) {
1234                 sb = get_super(pkt_bdev);
1235                 bdput(pkt_bdev);
1236         }
1237
1238         if (!sb)
1239                 return 0;
1240
1241         if (!sb->s_op || !sb->s_op->relocate_blocks)
1242                 goto out;
1243
1244         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1245         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1246                 goto out;
1247
1248         new_sector = new_block * (CD_FRAMESIZE >> 9);
1249         pkt->sector = new_sector;
1250
1251         pkt->bio->bi_sector = new_sector;
1252         pkt->bio->bi_next = NULL;
1253         pkt->bio->bi_flags = 1 << BIO_UPTODATE;
1254         pkt->bio->bi_idx = 0;
1255
1256         BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
1257         BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
1258         BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
1259         BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
1260         BUG_ON(pkt->bio->bi_private != pkt);
1261
1262         drop_super(sb);
1263         return 1;
1264
1265 out:
1266         drop_super(sb);
1267         return 0;
1268 #endif
1269 }
1270
1271 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1272 {
1273 #if PACKET_DEBUG > 1
1274         static const char *state_name[] = {
1275                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1276         };
1277         enum packet_data_state old_state = pkt->state;
1278         VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
1279                 state_name[old_state], state_name[state]);
1280 #endif
1281         pkt->state = state;
1282 }
1283
1284 /*
1285  * Scan the work queue to see if we can start a new packet.
1286  * returns non-zero if any work was done.
1287  */
1288 static int pkt_handle_queue(struct pktcdvd_device *pd)
1289 {
1290         struct packet_data *pkt, *p;
1291         struct bio *bio = NULL;
1292         sector_t zone = 0; /* Suppress gcc warning */
1293         struct pkt_rb_node *node, *first_node;
1294         struct rb_node *n;
1295         int wakeup;
1296
1297         VPRINTK("handle_queue\n");
1298
1299         atomic_set(&pd->scan_queue, 0);
1300
1301         if (list_empty(&pd->cdrw.pkt_free_list)) {
1302                 VPRINTK("handle_queue: no pkt\n");
1303                 return 0;
1304         }
1305
1306         /*
1307          * Try to find a zone we are not already working on.
1308          */
1309         spin_lock(&pd->lock);
1310         first_node = pkt_rbtree_find(pd, pd->current_sector);
1311         if (!first_node) {
1312                 n = rb_first(&pd->bio_queue);
1313                 if (n)
1314                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1315         }
1316         node = first_node;
1317         while (node) {
1318                 bio = node->bio;
1319                 zone = ZONE(bio->bi_sector, pd);
1320                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1321                         if (p->sector == zone) {
1322                                 bio = NULL;
1323                                 goto try_next_bio;
1324                         }
1325                 }
1326                 break;
1327 try_next_bio:
1328                 node = pkt_rbtree_next(node);
1329                 if (!node) {
1330                         n = rb_first(&pd->bio_queue);
1331                         if (n)
1332                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1333                 }
1334                 if (node == first_node)
1335                         node = NULL;
1336         }
1337         spin_unlock(&pd->lock);
1338         if (!bio) {
1339                 VPRINTK("handle_queue: no bio\n");
1340                 return 0;
1341         }
1342
1343         pkt = pkt_get_packet_data(pd, zone);
1344
1345         pd->current_sector = zone + pd->settings.size;
1346         pkt->sector = zone;
1347         BUG_ON(pkt->frames != pd->settings.size >> 2);
1348         pkt->write_size = 0;
1349
1350         /*
1351          * Scan work queue for bios in the same zone and link them
1352          * to this packet.
1353          */
1354         spin_lock(&pd->lock);
1355         VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
1356         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1357                 bio = node->bio;
1358                 VPRINTK("pkt_handle_queue: found zone=%llx\n",
1359                         (unsigned long long)ZONE(bio->bi_sector, pd));
1360                 if (ZONE(bio->bi_sector, pd) != zone)
1361                         break;
1362                 pkt_rbtree_erase(pd, node);
1363                 spin_lock(&pkt->lock);
1364                 pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
1365                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
1366                 spin_unlock(&pkt->lock);
1367         }
1368         /* check write congestion marks, and if bio_queue_size is
1369            below, wake up any waiters */
1370         wakeup = (pd->write_congestion_on > 0
1371                         && pd->bio_queue_size <= pd->write_congestion_off);
1372         spin_unlock(&pd->lock);
1373         if (wakeup)
1374                 clear_bdi_congested(&pd->disk->queue->backing_dev_info, WRITE);
1375
1376         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1377         pkt_set_state(pkt, PACKET_WAITING_STATE);
1378         atomic_set(&pkt->run_sm, 1);
1379
1380         spin_lock(&pd->cdrw.active_list_lock);
1381         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1382         spin_unlock(&pd->cdrw.active_list_lock);
1383
1384         return 1;
1385 }
1386
1387 /*
1388  * Assemble a bio to write one packet and queue the bio for processing
1389  * by the underlying block device.
1390  */
1391 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1392 {
1393         struct bio *bio;
1394         int f;
1395         int frames_write;
1396         struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1397
1398         for (f = 0; f < pkt->frames; f++) {
1399                 bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1400                 bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1401         }
1402
1403         /*
1404          * Fill-in bvec with data from orig_bios.
1405          */
1406         frames_write = 0;
1407         spin_lock(&pkt->lock);
1408         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1409                 int segment = bio->bi_idx;
1410                 int src_offs = 0;
1411                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1412                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1413                 BUG_ON(first_frame < 0);
1414                 BUG_ON(first_frame + num_frames > pkt->frames);
1415                 for (f = first_frame; f < first_frame + num_frames; f++) {
1416                         struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
1417
1418                         while (src_offs >= src_bvl->bv_len) {
1419                                 src_offs -= src_bvl->bv_len;
1420                                 segment++;
1421                                 BUG_ON(segment >= bio->bi_vcnt);
1422                                 src_bvl = bio_iovec_idx(bio, segment);
1423                         }
1424
1425                         if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
1426                                 bvec[f].bv_page = src_bvl->bv_page;
1427                                 bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
1428                         } else {
1429                                 pkt_copy_bio_data(bio, segment, src_offs,
1430                                                   bvec[f].bv_page, bvec[f].bv_offset);
1431                         }
1432                         src_offs += CD_FRAMESIZE;
1433                         frames_write++;
1434                 }
1435         }
1436         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1437         spin_unlock(&pkt->lock);
1438
1439         VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
1440                 frames_write, (unsigned long long)pkt->sector);
1441         BUG_ON(frames_write != pkt->write_size);
1442
1443         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1444                 pkt_make_local_copy(pkt, bvec);
1445                 pkt->cache_valid = 1;
1446         } else {
1447                 pkt->cache_valid = 0;
1448         }
1449
1450         /* Start the write request */
1451         bio_init(pkt->w_bio);
1452         pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
1453         pkt->w_bio->bi_sector = pkt->sector;
1454         pkt->w_bio->bi_bdev = pd->bdev;
1455         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1456         pkt->w_bio->bi_private = pkt;
1457         pkt->w_bio->bi_io_vec = bvec;
1458         pkt->w_bio->bi_destructor = pkt_bio_destructor;
1459         for (f = 0; f < pkt->frames; f++)
1460                 if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1461                         BUG();
1462         VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
1463
1464         atomic_set(&pkt->io_wait, 1);
1465         pkt->w_bio->bi_rw = WRITE;
1466         pkt_queue_bio(pd, pkt->w_bio);
1467 }
1468
1469 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1470 {
1471         struct bio *bio, *next;
1472
1473         if (!uptodate)
1474                 pkt->cache_valid = 0;
1475
1476         /* Finish all bios corresponding to this packet */
1477         bio = pkt->orig_bios;
1478         while (bio) {
1479                 next = bio->bi_next;
1480                 bio->bi_next = NULL;
1481                 bio_endio(bio, uptodate ? 0 : -EIO);
1482                 bio = next;
1483         }
1484         pkt->orig_bios = pkt->orig_bios_tail = NULL;
1485 }
1486
1487 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1488 {
1489         int uptodate;
1490
1491         VPRINTK("run_state_machine: pkt %d\n", pkt->id);
1492
1493         for (;;) {
1494                 switch (pkt->state) {
1495                 case PACKET_WAITING_STATE:
1496                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1497                                 return;
1498
1499                         pkt->sleep_time = 0;
1500                         pkt_gather_data(pd, pkt);
1501                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1502                         break;
1503
1504                 case PACKET_READ_WAIT_STATE:
1505                         if (atomic_read(&pkt->io_wait) > 0)
1506                                 return;
1507
1508                         if (atomic_read(&pkt->io_errors) > 0) {
1509                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1510                         } else {
1511                                 pkt_start_write(pd, pkt);
1512                         }
1513                         break;
1514
1515                 case PACKET_WRITE_WAIT_STATE:
1516                         if (atomic_read(&pkt->io_wait) > 0)
1517                                 return;
1518
1519                         if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1520                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1521                         } else {
1522                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1523                         }
1524                         break;
1525
1526                 case PACKET_RECOVERY_STATE:
1527                         if (pkt_start_recovery(pkt)) {
1528                                 pkt_start_write(pd, pkt);
1529                         } else {
1530                                 VPRINTK("No recovery possible\n");
1531                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1532                         }
1533                         break;
1534
1535                 case PACKET_FINISHED_STATE:
1536                         uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1537                         pkt_finish_packet(pkt, uptodate);
1538                         return;
1539
1540                 default:
1541                         BUG();
1542                         break;
1543                 }
1544         }
1545 }
1546
1547 static void pkt_handle_packets(struct pktcdvd_device *pd)
1548 {
1549         struct packet_data *pkt, *next;
1550
1551         VPRINTK("pkt_handle_packets\n");
1552
1553         /*
1554          * Run state machine for active packets
1555          */
1556         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1557                 if (atomic_read(&pkt->run_sm) > 0) {
1558                         atomic_set(&pkt->run_sm, 0);
1559                         pkt_run_state_machine(pd, pkt);
1560                 }
1561         }
1562
1563         /*
1564          * Move no longer active packets to the free list
1565          */
1566         spin_lock(&pd->cdrw.active_list_lock);
1567         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1568                 if (pkt->state == PACKET_FINISHED_STATE) {
1569                         list_del(&pkt->list);
1570                         pkt_put_packet_data(pd, pkt);
1571                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1572                         atomic_set(&pd->scan_queue, 1);
1573                 }
1574         }
1575         spin_unlock(&pd->cdrw.active_list_lock);
1576 }
1577
1578 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1579 {
1580         struct packet_data *pkt;
1581         int i;
1582
1583         for (i = 0; i < PACKET_NUM_STATES; i++)
1584                 states[i] = 0;
1585
1586         spin_lock(&pd->cdrw.active_list_lock);
1587         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1588                 states[pkt->state]++;
1589         }
1590         spin_unlock(&pd->cdrw.active_list_lock);
1591 }
1592
1593 /*
1594  * kcdrwd is woken up when writes have been queued for one of our
1595  * registered devices
1596  */
1597 static int kcdrwd(void *foobar)
1598 {
1599         struct pktcdvd_device *pd = foobar;
1600         struct packet_data *pkt;
1601         long min_sleep_time, residue;
1602
1603         set_user_nice(current, -20);
1604         set_freezable();
1605
1606         for (;;) {
1607                 DECLARE_WAITQUEUE(wait, current);
1608
1609                 /*
1610                  * Wait until there is something to do
1611                  */
1612                 add_wait_queue(&pd->wqueue, &wait);
1613                 for (;;) {
1614                         set_current_state(TASK_INTERRUPTIBLE);
1615
1616                         /* Check if we need to run pkt_handle_queue */
1617                         if (atomic_read(&pd->scan_queue) > 0)
1618                                 goto work_to_do;
1619
1620                         /* Check if we need to run the state machine for some packet */
1621                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1622                                 if (atomic_read(&pkt->run_sm) > 0)
1623                                         goto work_to_do;
1624                         }
1625
1626                         /* Check if we need to process the iosched queues */
1627                         if (atomic_read(&pd->iosched.attention) != 0)
1628                                 goto work_to_do;
1629
1630                         /* Otherwise, go to sleep */
1631                         if (PACKET_DEBUG > 1) {
1632                                 int states[PACKET_NUM_STATES];
1633                                 pkt_count_states(pd, states);
1634                                 VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1635                                         states[0], states[1], states[2], states[3],
1636                                         states[4], states[5]);
1637                         }
1638
1639                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1640                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1641                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1642                                         min_sleep_time = pkt->sleep_time;
1643                         }
1644
1645                         generic_unplug_device(bdev_get_queue(pd->bdev));
1646
1647                         VPRINTK("kcdrwd: sleeping\n");
1648                         residue = schedule_timeout(min_sleep_time);
1649                         VPRINTK("kcdrwd: wake up\n");
1650
1651                         /* make swsusp happy with our thread */
1652                         try_to_freeze();
1653
1654                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1655                                 if (!pkt->sleep_time)
1656                                         continue;
1657                                 pkt->sleep_time -= min_sleep_time - residue;
1658                                 if (pkt->sleep_time <= 0) {
1659                                         pkt->sleep_time = 0;
1660                                         atomic_inc(&pkt->run_sm);
1661                                 }
1662                         }
1663
1664                         if (kthread_should_stop())
1665                                 break;
1666                 }
1667 work_to_do:
1668                 set_current_state(TASK_RUNNING);
1669                 remove_wait_queue(&pd->wqueue, &wait);
1670
1671                 if (kthread_should_stop())
1672                         break;
1673
1674                 /*
1675                  * if pkt_handle_queue returns true, we can queue
1676                  * another request.
1677                  */
1678                 while (pkt_handle_queue(pd))
1679                         ;
1680
1681                 /*
1682                  * Handle packet state machine
1683                  */
1684                 pkt_handle_packets(pd);
1685
1686                 /*
1687                  * Handle iosched queues
1688                  */
1689                 pkt_iosched_process_queue(pd);
1690         }
1691
1692         return 0;
1693 }
1694
1695 static void pkt_print_settings(struct pktcdvd_device *pd)
1696 {
1697         printk(DRIVER_NAME": %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
1698         printk("%u blocks, ", pd->settings.size >> 2);
1699         printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
1700 }
1701
1702 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1703 {
1704         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1705
1706         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1707         cgc->cmd[2] = page_code | (page_control << 6);
1708         cgc->cmd[7] = cgc->buflen >> 8;
1709         cgc->cmd[8] = cgc->buflen & 0xff;
1710         cgc->data_direction = CGC_DATA_READ;
1711         return pkt_generic_packet(pd, cgc);
1712 }
1713
1714 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1715 {
1716         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1717         memset(cgc->buffer, 0, 2);
1718         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1719         cgc->cmd[1] = 0x10;             /* PF */
1720         cgc->cmd[7] = cgc->buflen >> 8;
1721         cgc->cmd[8] = cgc->buflen & 0xff;
1722         cgc->data_direction = CGC_DATA_WRITE;
1723         return pkt_generic_packet(pd, cgc);
1724 }
1725
1726 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1727 {
1728         struct packet_command cgc;
1729         int ret;
1730
1731         /* set up command and get the disc info */
1732         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1733         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1734         cgc.cmd[8] = cgc.buflen = 2;
1735         cgc.quiet = 1;
1736
1737         if ((ret = pkt_generic_packet(pd, &cgc)))
1738                 return ret;
1739
1740         /* not all drives have the same disc_info length, so requeue
1741          * packet with the length the drive tells us it can supply
1742          */
1743         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1744                      sizeof(di->disc_information_length);
1745
1746         if (cgc.buflen > sizeof(disc_information))
1747                 cgc.buflen = sizeof(disc_information);
1748
1749         cgc.cmd[8] = cgc.buflen;
1750         return pkt_generic_packet(pd, &cgc);
1751 }
1752
1753 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1754 {
1755         struct packet_command cgc;
1756         int ret;
1757
1758         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1759         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1760         cgc.cmd[1] = type & 3;
1761         cgc.cmd[4] = (track & 0xff00) >> 8;
1762         cgc.cmd[5] = track & 0xff;
1763         cgc.cmd[8] = 8;
1764         cgc.quiet = 1;
1765
1766         if ((ret = pkt_generic_packet(pd, &cgc)))
1767                 return ret;
1768
1769         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1770                      sizeof(ti->track_information_length);
1771
1772         if (cgc.buflen > sizeof(track_information))
1773                 cgc.buflen = sizeof(track_information);
1774
1775         cgc.cmd[8] = cgc.buflen;
1776         return pkt_generic_packet(pd, &cgc);
1777 }
1778
1779 static int pkt_get_last_written(struct pktcdvd_device *pd, long *last_written)
1780 {
1781         disc_information di;
1782         track_information ti;
1783         __u32 last_track;
1784         int ret = -1;
1785
1786         if ((ret = pkt_get_disc_info(pd, &di)))
1787                 return ret;
1788
1789         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1790         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1791                 return ret;
1792
1793         /* if this track is blank, try the previous. */
1794         if (ti.blank) {
1795                 last_track--;
1796                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1797                         return ret;
1798         }
1799
1800         /* if last recorded field is valid, return it. */
1801         if (ti.lra_v) {
1802                 *last_written = be32_to_cpu(ti.last_rec_address);
1803         } else {
1804                 /* make it up instead */
1805                 *last_written = be32_to_cpu(ti.track_start) +
1806                                 be32_to_cpu(ti.track_size);
1807                 if (ti.free_blocks)
1808                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1809         }
1810         return 0;
1811 }
1812
1813 /*
1814  * write mode select package based on pd->settings
1815  */
1816 static int pkt_set_write_settings(struct pktcdvd_device *pd)
1817 {
1818         struct packet_command cgc;
1819         struct request_sense sense;
1820         write_param_page *wp;
1821         char buffer[128];
1822         int ret, size;
1823
1824         /* doesn't apply to DVD+RW or DVD-RAM */
1825         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1826                 return 0;
1827
1828         memset(buffer, 0, sizeof(buffer));
1829         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1830         cgc.sense = &sense;
1831         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1832                 pkt_dump_sense(&cgc);
1833                 return ret;
1834         }
1835
1836         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1837         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1838         if (size > sizeof(buffer))
1839                 size = sizeof(buffer);
1840
1841         /*
1842          * now get it all
1843          */
1844         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1845         cgc.sense = &sense;
1846         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1847                 pkt_dump_sense(&cgc);
1848                 return ret;
1849         }
1850
1851         /*
1852          * write page is offset header + block descriptor length
1853          */
1854         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1855
1856         wp->fp = pd->settings.fp;
1857         wp->track_mode = pd->settings.track_mode;
1858         wp->write_type = pd->settings.write_type;
1859         wp->data_block_type = pd->settings.block_mode;
1860
1861         wp->multi_session = 0;
1862
1863 #ifdef PACKET_USE_LS
1864         wp->link_size = 7;
1865         wp->ls_v = 1;
1866 #endif
1867
1868         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1869                 wp->session_format = 0;
1870                 wp->subhdr2 = 0x20;
1871         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1872                 wp->session_format = 0x20;
1873                 wp->subhdr2 = 8;
1874 #if 0
1875                 wp->mcn[0] = 0x80;
1876                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1877 #endif
1878         } else {
1879                 /*
1880                  * paranoia
1881                  */
1882                 printk(DRIVER_NAME": write mode wrong %d\n", wp->data_block_type);
1883                 return 1;
1884         }
1885         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1886
1887         cgc.buflen = cgc.cmd[8] = size;
1888         if ((ret = pkt_mode_select(pd, &cgc))) {
1889                 pkt_dump_sense(&cgc);
1890                 return ret;
1891         }
1892
1893         pkt_print_settings(pd);
1894         return 0;
1895 }
1896
1897 /*
1898  * 1 -- we can write to this track, 0 -- we can't
1899  */
1900 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1901 {
1902         switch (pd->mmc3_profile) {
1903                 case 0x1a: /* DVD+RW */
1904                 case 0x12: /* DVD-RAM */
1905                         /* The track is always writable on DVD+RW/DVD-RAM */
1906                         return 1;
1907                 default:
1908                         break;
1909         }
1910
1911         if (!ti->packet || !ti->fp)
1912                 return 0;
1913
1914         /*
1915          * "good" settings as per Mt Fuji.
1916          */
1917         if (ti->rt == 0 && ti->blank == 0)
1918                 return 1;
1919
1920         if (ti->rt == 0 && ti->blank == 1)
1921                 return 1;
1922
1923         if (ti->rt == 1 && ti->blank == 0)
1924                 return 1;
1925
1926         printk(DRIVER_NAME": bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1927         return 0;
1928 }
1929
1930 /*
1931  * 1 -- we can write to this disc, 0 -- we can't
1932  */
1933 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1934 {
1935         switch (pd->mmc3_profile) {
1936                 case 0x0a: /* CD-RW */
1937                 case 0xffff: /* MMC3 not supported */
1938                         break;
1939                 case 0x1a: /* DVD+RW */
1940                 case 0x13: /* DVD-RW */
1941                 case 0x12: /* DVD-RAM */
1942                         return 1;
1943                 default:
1944                         VPRINTK(DRIVER_NAME": Wrong disc profile (%x)\n", pd->mmc3_profile);
1945                         return 0;
1946         }
1947
1948         /*
1949          * for disc type 0xff we should probably reserve a new track.
1950          * but i'm not sure, should we leave this to user apps? probably.
1951          */
1952         if (di->disc_type == 0xff) {
1953                 printk(DRIVER_NAME": Unknown disc. No track?\n");
1954                 return 0;
1955         }
1956
1957         if (di->disc_type != 0x20 && di->disc_type != 0) {
1958                 printk(DRIVER_NAME": Wrong disc type (%x)\n", di->disc_type);
1959                 return 0;
1960         }
1961
1962         if (di->erasable == 0) {
1963                 printk(DRIVER_NAME": Disc not erasable\n");
1964                 return 0;
1965         }
1966
1967         if (di->border_status == PACKET_SESSION_RESERVED) {
1968                 printk(DRIVER_NAME": Can't write to last track (reserved)\n");
1969                 return 0;
1970         }
1971
1972         return 1;
1973 }
1974
1975 static int pkt_probe_settings(struct pktcdvd_device *pd)
1976 {
1977         struct packet_command cgc;
1978         unsigned char buf[12];
1979         disc_information di;
1980         track_information ti;
1981         int ret, track;
1982
1983         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1984         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1985         cgc.cmd[8] = 8;
1986         ret = pkt_generic_packet(pd, &cgc);
1987         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1988
1989         memset(&di, 0, sizeof(disc_information));
1990         memset(&ti, 0, sizeof(track_information));
1991
1992         if ((ret = pkt_get_disc_info(pd, &di))) {
1993                 printk("failed get_disc\n");
1994                 return ret;
1995         }
1996
1997         if (!pkt_writable_disc(pd, &di))
1998                 return -EROFS;
1999
2000         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
2001
2002         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
2003         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
2004                 printk(DRIVER_NAME": failed get_track\n");
2005                 return ret;
2006         }
2007
2008         if (!pkt_writable_track(pd, &ti)) {
2009                 printk(DRIVER_NAME": can't write to this track\n");
2010                 return -EROFS;
2011         }
2012
2013         /*
2014          * we keep packet size in 512 byte units, makes it easier to
2015          * deal with request calculations.
2016          */
2017         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
2018         if (pd->settings.size == 0) {
2019                 printk(DRIVER_NAME": detected zero packet size!\n");
2020                 return -ENXIO;
2021         }
2022         if (pd->settings.size > PACKET_MAX_SECTORS) {
2023                 printk(DRIVER_NAME": packet size is too big\n");
2024                 return -EROFS;
2025         }
2026         pd->settings.fp = ti.fp;
2027         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
2028
2029         if (ti.nwa_v) {
2030                 pd->nwa = be32_to_cpu(ti.next_writable);
2031                 set_bit(PACKET_NWA_VALID, &pd->flags);
2032         }
2033
2034         /*
2035          * in theory we could use lra on -RW media as well and just zero
2036          * blocks that haven't been written yet, but in practice that
2037          * is just a no-go. we'll use that for -R, naturally.
2038          */
2039         if (ti.lra_v) {
2040                 pd->lra = be32_to_cpu(ti.last_rec_address);
2041                 set_bit(PACKET_LRA_VALID, &pd->flags);
2042         } else {
2043                 pd->lra = 0xffffffff;
2044                 set_bit(PACKET_LRA_VALID, &pd->flags);
2045         }
2046
2047         /*
2048          * fine for now
2049          */
2050         pd->settings.link_loss = 7;
2051         pd->settings.write_type = 0;    /* packet */
2052         pd->settings.track_mode = ti.track_mode;
2053
2054         /*
2055          * mode1 or mode2 disc
2056          */
2057         switch (ti.data_mode) {
2058                 case PACKET_MODE1:
2059                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
2060                         break;
2061                 case PACKET_MODE2:
2062                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
2063                         break;
2064                 default:
2065                         printk(DRIVER_NAME": unknown data mode\n");
2066                         return -EROFS;
2067         }
2068         return 0;
2069 }
2070
2071 /*
2072  * enable/disable write caching on drive
2073  */
2074 static int pkt_write_caching(struct pktcdvd_device *pd, int set)
2075 {
2076         struct packet_command cgc;
2077         struct request_sense sense;
2078         unsigned char buf[64];
2079         int ret;
2080
2081         memset(buf, 0, sizeof(buf));
2082         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
2083         cgc.sense = &sense;
2084         cgc.buflen = pd->mode_offset + 12;
2085
2086         /*
2087          * caching mode page might not be there, so quiet this command
2088          */
2089         cgc.quiet = 1;
2090
2091         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
2092                 return ret;
2093
2094         buf[pd->mode_offset + 10] |= (!!set << 2);
2095
2096         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
2097         ret = pkt_mode_select(pd, &cgc);
2098         if (ret) {
2099                 printk(DRIVER_NAME": write caching control failed\n");
2100                 pkt_dump_sense(&cgc);
2101         } else if (!ret && set)
2102                 printk(DRIVER_NAME": enabled write caching on %s\n", pd->name);
2103         return ret;
2104 }
2105
2106 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
2107 {
2108         struct packet_command cgc;
2109
2110         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2111         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
2112         cgc.cmd[4] = lockflag ? 1 : 0;
2113         return pkt_generic_packet(pd, &cgc);
2114 }
2115
2116 /*
2117  * Returns drive maximum write speed
2118  */
2119 static int pkt_get_max_speed(struct pktcdvd_device *pd, unsigned *write_speed)
2120 {
2121         struct packet_command cgc;
2122         struct request_sense sense;
2123         unsigned char buf[256+18];
2124         unsigned char *cap_buf;
2125         int ret, offset;
2126
2127         memset(buf, 0, sizeof(buf));
2128         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
2129         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
2130         cgc.sense = &sense;
2131
2132         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2133         if (ret) {
2134                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2135                              sizeof(struct mode_page_header);
2136                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2137                 if (ret) {
2138                         pkt_dump_sense(&cgc);
2139                         return ret;
2140                 }
2141         }
2142
2143         offset = 20;                        /* Obsoleted field, used by older drives */
2144         if (cap_buf[1] >= 28)
2145                 offset = 28;                /* Current write speed selected */
2146         if (cap_buf[1] >= 30) {
2147                 /* If the drive reports at least one "Logical Unit Write
2148                  * Speed Performance Descriptor Block", use the information
2149                  * in the first block. (contains the highest speed)
2150                  */
2151                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2152                 if (num_spdb > 0)
2153                         offset = 34;
2154         }
2155
2156         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2157         return 0;
2158 }
2159
2160 /* These tables from cdrecord - I don't have orange book */
2161 /* standard speed CD-RW (1-4x) */
2162 static char clv_to_speed[16] = {
2163         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2164            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2165 };
2166 /* high speed CD-RW (-10x) */
2167 static char hs_clv_to_speed[16] = {
2168         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2169            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2170 };
2171 /* ultra high speed CD-RW */
2172 static char us_clv_to_speed[16] = {
2173         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2174            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2175 };
2176
2177 /*
2178  * reads the maximum media speed from ATIP
2179  */
2180 static int pkt_media_speed(struct pktcdvd_device *pd, unsigned *speed)
2181 {
2182         struct packet_command cgc;
2183         struct request_sense sense;
2184         unsigned char buf[64];
2185         unsigned int size, st, sp;
2186         int ret;
2187
2188         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2189         cgc.sense = &sense;
2190         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2191         cgc.cmd[1] = 2;
2192         cgc.cmd[2] = 4; /* READ ATIP */
2193         cgc.cmd[8] = 2;
2194         ret = pkt_generic_packet(pd, &cgc);
2195         if (ret) {
2196                 pkt_dump_sense(&cgc);
2197                 return ret;
2198         }
2199         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2200         if (size > sizeof(buf))
2201                 size = sizeof(buf);
2202
2203         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2204         cgc.sense = &sense;
2205         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2206         cgc.cmd[1] = 2;
2207         cgc.cmd[2] = 4;
2208         cgc.cmd[8] = size;
2209         ret = pkt_generic_packet(pd, &cgc);
2210         if (ret) {
2211                 pkt_dump_sense(&cgc);
2212                 return ret;
2213         }
2214
2215         if (!buf[6] & 0x40) {
2216                 printk(DRIVER_NAME": Disc type is not CD-RW\n");
2217                 return 1;
2218         }
2219         if (!buf[6] & 0x4) {
2220                 printk(DRIVER_NAME": A1 values on media are not valid, maybe not CDRW?\n");
2221                 return 1;
2222         }
2223
2224         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2225
2226         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2227
2228         /* Info from cdrecord */
2229         switch (st) {
2230                 case 0: /* standard speed */
2231                         *speed = clv_to_speed[sp];
2232                         break;
2233                 case 1: /* high speed */
2234                         *speed = hs_clv_to_speed[sp];
2235                         break;
2236                 case 2: /* ultra high speed */
2237                         *speed = us_clv_to_speed[sp];
2238                         break;
2239                 default:
2240                         printk(DRIVER_NAME": Unknown disc sub-type %d\n",st);
2241                         return 1;
2242         }
2243         if (*speed) {
2244                 printk(DRIVER_NAME": Max. media speed: %d\n",*speed);
2245                 return 0;
2246         } else {
2247                 printk(DRIVER_NAME": Unknown speed %d for sub-type %d\n",sp,st);
2248                 return 1;
2249         }
2250 }
2251
2252 static int pkt_perform_opc(struct pktcdvd_device *pd)
2253 {
2254         struct packet_command cgc;
2255         struct request_sense sense;
2256         int ret;
2257
2258         VPRINTK(DRIVER_NAME": Performing OPC\n");
2259
2260         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2261         cgc.sense = &sense;
2262         cgc.timeout = 60*HZ;
2263         cgc.cmd[0] = GPCMD_SEND_OPC;
2264         cgc.cmd[1] = 1;
2265         if ((ret = pkt_generic_packet(pd, &cgc)))
2266                 pkt_dump_sense(&cgc);
2267         return ret;
2268 }
2269
2270 static int pkt_open_write(struct pktcdvd_device *pd)
2271 {
2272         int ret;
2273         unsigned int write_speed, media_write_speed, read_speed;
2274
2275         if ((ret = pkt_probe_settings(pd))) {
2276                 VPRINTK(DRIVER_NAME": %s failed probe\n", pd->name);
2277                 return ret;
2278         }
2279
2280         if ((ret = pkt_set_write_settings(pd))) {
2281                 DPRINTK(DRIVER_NAME": %s failed saving write settings\n", pd->name);
2282                 return -EIO;
2283         }
2284
2285         pkt_write_caching(pd, USE_WCACHING);
2286
2287         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2288                 write_speed = 16 * 177;
2289         switch (pd->mmc3_profile) {
2290                 case 0x13: /* DVD-RW */
2291                 case 0x1a: /* DVD+RW */
2292                 case 0x12: /* DVD-RAM */
2293                         DPRINTK(DRIVER_NAME": write speed %ukB/s\n", write_speed);
2294                         break;
2295                 default:
2296                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2297                                 media_write_speed = 16;
2298                         write_speed = min(write_speed, media_write_speed * 177);
2299                         DPRINTK(DRIVER_NAME": write speed %ux\n", write_speed / 176);
2300                         break;
2301         }
2302         read_speed = write_speed;
2303
2304         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2305                 DPRINTK(DRIVER_NAME": %s couldn't set write speed\n", pd->name);
2306                 return -EIO;
2307         }
2308         pd->write_speed = write_speed;
2309         pd->read_speed = read_speed;
2310
2311         if ((ret = pkt_perform_opc(pd))) {
2312                 DPRINTK(DRIVER_NAME": %s Optimum Power Calibration failed\n", pd->name);
2313         }
2314
2315         return 0;
2316 }
2317
2318 /*
2319  * called at open time.
2320  */
2321 static int pkt_open_dev(struct pktcdvd_device *pd, int write)
2322 {
2323         int ret;
2324         long lba;
2325         struct request_queue *q;
2326
2327         /*
2328          * We need to re-open the cdrom device without O_NONBLOCK to be able
2329          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2330          * so bdget() can't fail.
2331          */
2332         bdget(pd->bdev->bd_dev);
2333         if ((ret = blkdev_get(pd->bdev, FMODE_READ, O_RDONLY)))
2334                 goto out;
2335
2336         if ((ret = bd_claim(pd->bdev, pd)))
2337                 goto out_putdev;
2338
2339         if ((ret = pkt_get_last_written(pd, &lba))) {
2340                 printk(DRIVER_NAME": pkt_get_last_written failed\n");
2341                 goto out_unclaim;
2342         }
2343
2344         set_capacity(pd->disk, lba << 2);
2345         set_capacity(pd->bdev->bd_disk, lba << 2);
2346         bd_set_size(pd->bdev, (loff_t)lba << 11);
2347
2348         q = bdev_get_queue(pd->bdev);
2349         if (write) {
2350                 if ((ret = pkt_open_write(pd)))
2351                         goto out_unclaim;
2352                 /*
2353                  * Some CDRW drives can not handle writes larger than one packet,
2354                  * even if the size is a multiple of the packet size.
2355                  */
2356                 spin_lock_irq(q->queue_lock);
2357                 blk_queue_max_sectors(q, pd->settings.size);
2358                 spin_unlock_irq(q->queue_lock);
2359                 set_bit(PACKET_WRITABLE, &pd->flags);
2360         } else {
2361                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2362                 clear_bit(PACKET_WRITABLE, &pd->flags);
2363         }
2364
2365         if ((ret = pkt_set_segment_merging(pd, q)))
2366                 goto out_unclaim;
2367
2368         if (write) {
2369                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2370                         printk(DRIVER_NAME": not enough memory for buffers\n");
2371                         ret = -ENOMEM;
2372                         goto out_unclaim;
2373                 }
2374                 printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
2375         }
2376
2377         return 0;
2378
2379 out_unclaim:
2380         bd_release(pd->bdev);
2381 out_putdev:
2382         blkdev_put(pd->bdev);
2383 out:
2384         return ret;
2385 }
2386
2387 /*
2388  * called when the device is closed. makes sure that the device flushes
2389  * the internal cache before we close.
2390  */
2391 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2392 {
2393         if (flush && pkt_flush_cache(pd))
2394                 DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
2395
2396         pkt_lock_door(pd, 0);
2397
2398         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2399         bd_release(pd->bdev);
2400         blkdev_put(pd->bdev);
2401
2402         pkt_shrink_pktlist(pd);
2403 }
2404
2405 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
2406 {
2407         if (dev_minor >= MAX_WRITERS)
2408                 return NULL;
2409         return pkt_devs[dev_minor];
2410 }
2411
2412 static int pkt_open(struct inode *inode, struct file *file)
2413 {
2414         struct pktcdvd_device *pd = NULL;
2415         int ret;
2416
2417         VPRINTK(DRIVER_NAME": entering open\n");
2418
2419         mutex_lock(&ctl_mutex);
2420         pd = pkt_find_dev_from_minor(iminor(inode));
2421         if (!pd) {
2422                 ret = -ENODEV;
2423                 goto out;
2424         }
2425         BUG_ON(pd->refcnt < 0);
2426
2427         pd->refcnt++;
2428         if (pd->refcnt > 1) {
2429                 if ((file->f_mode & FMODE_WRITE) &&
2430                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2431                         ret = -EBUSY;
2432                         goto out_dec;
2433                 }
2434         } else {
2435                 ret = pkt_open_dev(pd, file->f_mode & FMODE_WRITE);
2436                 if (ret)
2437                         goto out_dec;
2438                 /*
2439                  * needed here as well, since ext2 (among others) may change
2440                  * the blocksize at mount time
2441                  */
2442                 set_blocksize(inode->i_bdev, CD_FRAMESIZE);
2443         }
2444
2445         mutex_unlock(&ctl_mutex);
2446         return 0;
2447
2448 out_dec:
2449         pd->refcnt--;
2450 out:
2451         VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
2452         mutex_unlock(&ctl_mutex);
2453         return ret;
2454 }
2455
2456 static int pkt_close(struct inode *inode, struct file *file)
2457 {
2458         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2459         int ret = 0;
2460
2461         mutex_lock(&ctl_mutex);
2462         pd->refcnt--;
2463         BUG_ON(pd->refcnt < 0);
2464         if (pd->refcnt == 0) {
2465                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2466                 pkt_release_dev(pd, flush);
2467         }
2468         mutex_unlock(&ctl_mutex);
2469         return ret;
2470 }
2471
2472
2473 static void pkt_end_io_read_cloned(struct bio *bio, int err)
2474 {
2475         struct packet_stacked_data *psd = bio->bi_private;
2476         struct pktcdvd_device *pd = psd->pd;
2477
2478         bio_put(bio);
2479         bio_endio(psd->bio, err);
2480         mempool_free(psd, psd_pool);
2481         pkt_bio_finished(pd);
2482 }
2483
2484 static int pkt_make_request(struct request_queue *q, struct bio *bio)
2485 {
2486         struct pktcdvd_device *pd;
2487         char b[BDEVNAME_SIZE];
2488         sector_t zone;
2489         struct packet_data *pkt;
2490         int was_empty, blocked_bio;
2491         struct pkt_rb_node *node;
2492
2493         pd = q->queuedata;
2494         if (!pd) {
2495                 printk(DRIVER_NAME": %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
2496                 goto end_io;
2497         }
2498
2499         /*
2500          * Clone READ bios so we can have our own bi_end_io callback.
2501          */
2502         if (bio_data_dir(bio) == READ) {
2503                 struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2504                 struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2505
2506                 psd->pd = pd;
2507                 psd->bio = bio;
2508                 cloned_bio->bi_bdev = pd->bdev;
2509                 cloned_bio->bi_private = psd;
2510                 cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2511                 pd->stats.secs_r += bio->bi_size >> 9;
2512                 pkt_queue_bio(pd, cloned_bio);
2513                 return 0;
2514         }
2515
2516         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2517                 printk(DRIVER_NAME": WRITE for ro device %s (%llu)\n",
2518                         pd->name, (unsigned long long)bio->bi_sector);
2519                 goto end_io;
2520         }
2521
2522         if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
2523                 printk(DRIVER_NAME": wrong bio size\n");
2524                 goto end_io;
2525         }
2526
2527         blk_queue_bounce(q, &bio);
2528
2529         zone = ZONE(bio->bi_sector, pd);
2530         VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
2531                 (unsigned long long)bio->bi_sector,
2532                 (unsigned long long)(bio->bi_sector + bio_sectors(bio)));
2533
2534         /* Check if we have to split the bio */
2535         {
2536                 struct bio_pair *bp;
2537                 sector_t last_zone;
2538                 int first_sectors;
2539
2540                 last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
2541                 if (last_zone != zone) {
2542                         BUG_ON(last_zone != zone + pd->settings.size);
2543                         first_sectors = last_zone - bio->bi_sector;
2544                         bp = bio_split(bio, bio_split_pool, first_sectors);
2545                         BUG_ON(!bp);
2546                         pkt_make_request(q, &bp->bio1);
2547                         pkt_make_request(q, &bp->bio2);
2548                         bio_pair_release(bp);
2549                         return 0;
2550                 }
2551         }
2552
2553         /*
2554          * If we find a matching packet in state WAITING or READ_WAIT, we can
2555          * just append this bio to that packet.
2556          */
2557         spin_lock(&pd->cdrw.active_list_lock);
2558         blocked_bio = 0;
2559         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2560                 if (pkt->sector == zone) {
2561                         spin_lock(&pkt->lock);
2562                         if ((pkt->state == PACKET_WAITING_STATE) ||
2563                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2564                                 pkt_add_list_last(bio, &pkt->orig_bios,
2565                                                   &pkt->orig_bios_tail);
2566                                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
2567                                 if ((pkt->write_size >= pkt->frames) &&
2568                                     (pkt->state == PACKET_WAITING_STATE)) {
2569                                         atomic_inc(&pkt->run_sm);
2570                                         wake_up(&pd->wqueue);
2571                                 }
2572                                 spin_unlock(&pkt->lock);
2573                                 spin_unlock(&pd->cdrw.active_list_lock);
2574                                 return 0;
2575                         } else {
2576                                 blocked_bio = 1;
2577                         }
2578                         spin_unlock(&pkt->lock);
2579                 }
2580         }
2581         spin_unlock(&pd->cdrw.active_list_lock);
2582
2583         /*
2584          * Test if there is enough room left in the bio work queue
2585          * (queue size >= congestion on mark).
2586          * If not, wait till the work queue size is below the congestion off mark.
2587          */
2588         spin_lock(&pd->lock);
2589         if (pd->write_congestion_on > 0
2590             && pd->bio_queue_size >= pd->write_congestion_on) {
2591                 set_bdi_congested(&q->backing_dev_info, WRITE);
2592                 do {
2593                         spin_unlock(&pd->lock);
2594                         congestion_wait(WRITE, HZ);
2595                         spin_lock(&pd->lock);
2596                 } while(pd->bio_queue_size > pd->write_congestion_off);
2597         }
2598         spin_unlock(&pd->lock);
2599
2600         /*
2601          * No matching packet found. Store the bio in the work queue.
2602          */
2603         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2604         node->bio = bio;
2605         spin_lock(&pd->lock);
2606         BUG_ON(pd->bio_queue_size < 0);
2607         was_empty = (pd->bio_queue_size == 0);
2608         pkt_rbtree_insert(pd, node);
2609         spin_unlock(&pd->lock);
2610
2611         /*
2612          * Wake up the worker thread.
2613          */
2614         atomic_set(&pd->scan_queue, 1);
2615         if (was_empty) {
2616                 /* This wake_up is required for correct operation */
2617                 wake_up(&pd->wqueue);
2618         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2619                 /*
2620                  * This wake up is not required for correct operation,
2621                  * but improves performance in some cases.
2622                  */
2623                 wake_up(&pd->wqueue);
2624         }
2625         return 0;
2626 end_io:
2627         bio_io_error(bio);
2628         return 0;
2629 }
2630
2631
2632
2633 static int pkt_merge_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *bvec)
2634 {
2635         struct pktcdvd_device *pd = q->queuedata;
2636         sector_t zone = ZONE(bio->bi_sector, pd);
2637         int used = ((bio->bi_sector - zone) << 9) + bio->bi_size;
2638         int remaining = (pd->settings.size << 9) - used;
2639         int remaining2;
2640
2641         /*
2642          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2643          * boundary, pkt_make_request() will split the bio.
2644          */
2645         remaining2 = PAGE_SIZE - bio->bi_size;
2646         remaining = max(remaining, remaining2);
2647
2648         BUG_ON(remaining < 0);
2649         return remaining;
2650 }
2651
2652 static void pkt_init_queue(struct pktcdvd_device *pd)
2653 {
2654         struct request_queue *q = pd->disk->queue;
2655
2656         blk_queue_make_request(q, pkt_make_request);
2657         blk_queue_hardsect_size(q, CD_FRAMESIZE);
2658         blk_queue_max_sectors(q, PACKET_MAX_SECTORS);
2659         blk_queue_merge_bvec(q, pkt_merge_bvec);
2660         q->queuedata = pd;
2661 }
2662
2663 static int pkt_seq_show(struct seq_file *m, void *p)
2664 {
2665         struct pktcdvd_device *pd = m->private;
2666         char *msg;
2667         char bdev_buf[BDEVNAME_SIZE];
2668         int states[PACKET_NUM_STATES];
2669
2670         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2671                    bdevname(pd->bdev, bdev_buf));
2672
2673         seq_printf(m, "\nSettings:\n");
2674         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2675
2676         if (pd->settings.write_type == 0)
2677                 msg = "Packet";
2678         else
2679                 msg = "Unknown";
2680         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2681
2682         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2683         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2684
2685         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2686
2687         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2688                 msg = "Mode 1";
2689         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2690                 msg = "Mode 2";
2691         else
2692                 msg = "Unknown";
2693         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2694
2695         seq_printf(m, "\nStatistics:\n");
2696         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2697         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2698         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2699         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2700         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2701
2702         seq_printf(m, "\nMisc:\n");
2703         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2704         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2705         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2706         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2707         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2708         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2709
2710         seq_printf(m, "\nQueue state:\n");
2711         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2712         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2713         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2714
2715         pkt_count_states(pd, states);
2716         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2717                    states[0], states[1], states[2], states[3], states[4], states[5]);
2718
2719         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2720                         pd->write_congestion_off,
2721                         pd->write_congestion_on);
2722         return 0;
2723 }
2724
2725 static int pkt_seq_open(struct inode *inode, struct file *file)
2726 {
2727         return single_open(file, pkt_seq_show, PDE(inode)->data);
2728 }
2729
2730 static const struct file_operations pkt_proc_fops = {
2731         .open   = pkt_seq_open,
2732         .read   = seq_read,
2733         .llseek = seq_lseek,
2734         .release = single_release
2735 };
2736
2737 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2738 {
2739         int i;
2740         int ret = 0;
2741         char b[BDEVNAME_SIZE];
2742         struct proc_dir_entry *proc;
2743         struct block_device *bdev;
2744
2745         if (pd->pkt_dev == dev) {
2746                 printk(DRIVER_NAME": Recursive setup not allowed\n");
2747                 return -EBUSY;
2748         }
2749         for (i = 0; i < MAX_WRITERS; i++) {
2750                 struct pktcdvd_device *pd2 = pkt_devs[i];
2751                 if (!pd2)
2752                         continue;
2753                 if (pd2->bdev->bd_dev == dev) {
2754                         printk(DRIVER_NAME": %s already setup\n", bdevname(pd2->bdev, b));
2755                         return -EBUSY;
2756                 }
2757                 if (pd2->pkt_dev == dev) {
2758                         printk(DRIVER_NAME": Can't chain pktcdvd devices\n");
2759                         return -EBUSY;
2760                 }
2761         }
2762
2763         bdev = bdget(dev);
2764         if (!bdev)
2765                 return -ENOMEM;
2766         ret = blkdev_get(bdev, FMODE_READ, O_RDONLY | O_NONBLOCK);
2767         if (ret)
2768                 return ret;
2769
2770         /* This is safe, since we have a reference from open(). */
2771         __module_get(THIS_MODULE);
2772
2773         pd->bdev = bdev;
2774         set_blocksize(bdev, CD_FRAMESIZE);
2775
2776         pkt_init_queue(pd);
2777
2778         atomic_set(&pd->cdrw.pending_bios, 0);
2779         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2780         if (IS_ERR(pd->cdrw.thread)) {
2781                 printk(DRIVER_NAME": can't start kernel thread\n");
2782                 ret = -ENOMEM;
2783                 goto out_mem;
2784         }
2785
2786         proc = create_proc_entry(pd->name, 0, pkt_proc);
2787         if (proc) {
2788                 proc->data = pd;
2789                 proc->proc_fops = &pkt_proc_fops;
2790         }
2791         DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
2792         return 0;
2793
2794 out_mem:
2795         blkdev_put(bdev);
2796         /* This is safe: open() is still holding a reference. */
2797         module_put(THIS_MODULE);
2798         return ret;
2799 }
2800
2801 static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
2802 {
2803         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2804
2805         VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd, imajor(inode), iminor(inode));
2806
2807         switch (cmd) {
2808         /*
2809          * forward selected CDROM ioctls to CD-ROM, for UDF
2810          */
2811         case CDROMMULTISESSION:
2812         case CDROMREADTOCENTRY:
2813         case CDROM_LAST_WRITTEN:
2814         case CDROM_SEND_PACKET:
2815         case SCSI_IOCTL_SEND_COMMAND:
2816                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2817
2818         case CDROMEJECT:
2819                 /*
2820                  * The door gets locked when the device is opened, so we
2821                  * have to unlock it or else the eject command fails.
2822                  */
2823                 if (pd->refcnt == 1)
2824                         pkt_lock_door(pd, 0);
2825                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2826
2827         default:
2828                 VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, cmd);
2829                 return -ENOTTY;
2830         }
2831
2832         return 0;
2833 }
2834
2835 static int pkt_media_changed(struct gendisk *disk)
2836 {
2837         struct pktcdvd_device *pd = disk->private_data;
2838         struct gendisk *attached_disk;
2839
2840         if (!pd)
2841                 return 0;
2842         if (!pd->bdev)
2843                 return 0;
2844         attached_disk = pd->bdev->bd_disk;
2845         if (!attached_disk)
2846                 return 0;
2847         return attached_disk->fops->media_changed(attached_disk);
2848 }
2849
2850 static struct block_device_operations pktcdvd_ops = {
2851         .owner =                THIS_MODULE,
2852         .open =                 pkt_open,
2853         .release =              pkt_close,
2854         .ioctl =                pkt_ioctl,
2855         .media_changed =        pkt_media_changed,
2856 };
2857
2858 /*
2859  * Set up mapping from pktcdvd device to CD-ROM device.
2860  */
2861 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2862 {
2863         int idx;
2864         int ret = -ENOMEM;
2865         struct pktcdvd_device *pd;
2866         struct gendisk *disk;
2867
2868         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2869
2870         for (idx = 0; idx < MAX_WRITERS; idx++)
2871                 if (!pkt_devs[idx])
2872                         break;
2873         if (idx == MAX_WRITERS) {
2874                 printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
2875                 ret = -EBUSY;
2876                 goto out_mutex;
2877         }
2878
2879         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2880         if (!pd)
2881                 goto out_mutex;
2882
2883         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2884                                                   sizeof(struct pkt_rb_node));
2885         if (!pd->rb_pool)
2886                 goto out_mem;
2887
2888         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2889         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2890         spin_lock_init(&pd->cdrw.active_list_lock);
2891
2892         spin_lock_init(&pd->lock);
2893         spin_lock_init(&pd->iosched.lock);
2894         sprintf(pd->name, DRIVER_NAME"%d", idx);
2895         init_waitqueue_head(&pd->wqueue);
2896         pd->bio_queue = RB_ROOT;
2897
2898         pd->write_congestion_on  = write_congestion_on;
2899         pd->write_congestion_off = write_congestion_off;
2900
2901         disk = alloc_disk(1);
2902         if (!disk)
2903                 goto out_mem;
2904         pd->disk = disk;
2905         disk->major = pktdev_major;
2906         disk->first_minor = idx;
2907         disk->fops = &pktcdvd_ops;
2908         disk->flags = GENHD_FL_REMOVABLE;
2909         strcpy(disk->disk_name, pd->name);
2910         disk->private_data = pd;
2911         disk->queue = blk_alloc_queue(GFP_KERNEL);
2912         if (!disk->queue)
2913                 goto out_mem2;
2914
2915         pd->pkt_dev = MKDEV(disk->major, disk->first_minor);
2916         ret = pkt_new_dev(pd, dev);
2917         if (ret)
2918                 goto out_new_dev;
2919
2920         add_disk(disk);
2921
2922         pkt_sysfs_dev_new(pd);
2923         pkt_debugfs_dev_new(pd);
2924
2925         pkt_devs[idx] = pd;
2926         if (pkt_dev)
2927                 *pkt_dev = pd->pkt_dev;
2928
2929         mutex_unlock(&ctl_mutex);
2930         return 0;
2931
2932 out_new_dev:
2933         blk_cleanup_queue(disk->queue);
2934 out_mem2:
2935         put_disk(disk);
2936 out_mem:
2937         if (pd->rb_pool)
2938                 mempool_destroy(pd->rb_pool);
2939         kfree(pd);
2940 out_mutex:
2941         mutex_unlock(&ctl_mutex);
2942         printk(DRIVER_NAME": setup of pktcdvd device failed\n");
2943         return ret;
2944 }
2945
2946 /*
2947  * Tear down mapping from pktcdvd device to CD-ROM device.
2948  */
2949 static int pkt_remove_dev(dev_t pkt_dev)
2950 {
2951         struct pktcdvd_device *pd;
2952         int idx;
2953         int ret = 0;
2954
2955         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2956
2957         for (idx = 0; idx < MAX_WRITERS; idx++) {
2958                 pd = pkt_devs[idx];
2959                 if (pd && (pd->pkt_dev == pkt_dev))
2960                         break;
2961         }
2962         if (idx == MAX_WRITERS) {
2963                 DPRINTK(DRIVER_NAME": dev not setup\n");
2964                 ret = -ENXIO;
2965                 goto out;
2966         }
2967
2968         if (pd->refcnt > 0) {
2969                 ret = -EBUSY;
2970                 goto out;
2971         }
2972         if (!IS_ERR(pd->cdrw.thread))
2973                 kthread_stop(pd->cdrw.thread);
2974
2975         pkt_devs[idx] = NULL;
2976
2977         pkt_debugfs_dev_remove(pd);
2978         pkt_sysfs_dev_remove(pd);
2979
2980         blkdev_put(pd->bdev);
2981
2982         remove_proc_entry(pd->name, pkt_proc);
2983         DPRINTK(DRIVER_NAME": writer %s unmapped\n", pd->name);
2984
2985         del_gendisk(pd->disk);
2986         blk_cleanup_queue(pd->disk->queue);
2987         put_disk(pd->disk);
2988
2989         mempool_destroy(pd->rb_pool);
2990         kfree(pd);
2991
2992         /* This is safe: open() is still holding a reference. */
2993         module_put(THIS_MODULE);
2994
2995 out:
2996         mutex_unlock(&ctl_mutex);
2997         return ret;
2998 }
2999
3000 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
3001 {
3002         struct pktcdvd_device *pd;
3003
3004         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3005
3006         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
3007         if (pd) {
3008                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
3009                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
3010         } else {
3011                 ctrl_cmd->dev = 0;
3012                 ctrl_cmd->pkt_dev = 0;
3013         }
3014         ctrl_cmd->num_devices = MAX_WRITERS;
3015
3016         mutex_unlock(&ctl_mutex);
3017 }
3018
3019 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
3020 {
3021         void __user *argp = (void __user *)arg;
3022         struct pkt_ctrl_command ctrl_cmd;
3023         int ret = 0;
3024         dev_t pkt_dev = 0;
3025
3026         if (cmd != PACKET_CTRL_CMD)
3027                 return -ENOTTY;
3028
3029         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
3030                 return -EFAULT;
3031
3032         switch (ctrl_cmd.command) {
3033         case PKT_CTRL_CMD_SETUP:
3034                 if (!capable(CAP_SYS_ADMIN))
3035                         return -EPERM;
3036                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
3037                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
3038                 break;
3039         case PKT_CTRL_CMD_TEARDOWN:
3040                 if (!capable(CAP_SYS_ADMIN))
3041                         return -EPERM;
3042                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
3043                 break;
3044         case PKT_CTRL_CMD_STATUS:
3045                 pkt_get_status(&ctrl_cmd);
3046                 break;
3047         default:
3048                 return -ENOTTY;
3049         }
3050
3051         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
3052                 return -EFAULT;
3053         return ret;
3054 }
3055
3056
3057 static const struct file_operations pkt_ctl_fops = {
3058         .ioctl   = pkt_ctl_ioctl,
3059         .owner   = THIS_MODULE,
3060 };
3061
3062 static struct miscdevice pkt_misc = {
3063         .minor          = MISC_DYNAMIC_MINOR,
3064         .name           = DRIVER_NAME,
3065         .fops           = &pkt_ctl_fops
3066 };
3067
3068 static int __init pkt_init(void)
3069 {
3070         int ret;
3071
3072         mutex_init(&ctl_mutex);
3073
3074         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
3075                                         sizeof(struct packet_stacked_data));
3076         if (!psd_pool)
3077                 return -ENOMEM;
3078
3079         ret = register_blkdev(pktdev_major, DRIVER_NAME);
3080         if (ret < 0) {
3081                 printk(DRIVER_NAME": Unable to register block device\n");
3082                 goto out2;
3083         }
3084         if (!pktdev_major)
3085                 pktdev_major = ret;
3086
3087         ret = pkt_sysfs_init();
3088         if (ret)
3089                 goto out;
3090
3091         pkt_debugfs_init();
3092
3093         ret = misc_register(&pkt_misc);
3094         if (ret) {
3095                 printk(DRIVER_NAME": Unable to register misc device\n");
3096                 goto out_misc;
3097         }
3098
3099         pkt_proc = proc_mkdir(DRIVER_NAME, proc_root_driver);
3100
3101         return 0;
3102
3103 out_misc:
3104         pkt_debugfs_cleanup();
3105         pkt_sysfs_cleanup();
3106 out:
3107         unregister_blkdev(pktdev_major, DRIVER_NAME);
3108 out2:
3109         mempool_destroy(psd_pool);
3110         return ret;
3111 }
3112
3113 static void __exit pkt_exit(void)
3114 {
3115         remove_proc_entry(DRIVER_NAME, proc_root_driver);
3116         misc_deregister(&pkt_misc);
3117
3118         pkt_debugfs_cleanup();
3119         pkt_sysfs_cleanup();
3120
3121         unregister_blkdev(pktdev_major, DRIVER_NAME);
3122         mempool_destroy(psd_pool);
3123 }
3124
3125 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3126 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3127 MODULE_LICENSE("GPL");
3128
3129 module_init(pkt_init);
3130 module_exit(pkt_exit);