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
 780         rq->timeout = 60*HZ;
 781         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 782         rq->cmd_flags |= REQ_HARDBARRIER;
 783         if (cgc->quiet)
 784                 rq->cmd_flags |= REQ_QUIET;
 785
 786         blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
 787         if (rq->errors)
 788                 ret = -EIO;
 789 out:
 790         blk_put_request(rq);
 791         return ret;
 792 }
 793
 794 /*
 795  * A generic sense dump / resolve mechanism should be implemented across
 796  * all ATAPI + SCSI devices.
 797  */
 798 static void pkt_dump_sense(struct packet_command *cgc)
 799 {
 800         static char *info[9] = { "No sense", "Recovered error", "Not ready",
 801                                  "Medium error", "Hardware error", "Illegal request",
 802                                  "Unit attention", "Data protect", "Blank check" };
 803         int i;
 804         struct request_sense *sense = cgc->sense;
 805
 806         printk(DRIVER_NAME":");
 807         for (i = 0; i < CDROM_PACKET_SIZE; i++)
 808                 printk(" %02x", cgc->cmd[i]);
 809         printk(" - ");
 810
 811         if (sense == NULL) {
 812                 printk("no sense\n");
 813                 return;
 814         }
 815
 816         printk("sense %02x.%02x.%02x", sense->sense_key, sense->asc, sense->ascq);
 817
 818         if (sense->sense_key > 8) {
 819                 printk(" (INVALID)\n");
 820                 return;
 821         }
 822
 823         printk(" (%s)\n", info[sense->sense_key]);
 824 }
 825
 826 /*
 827  * flush the drive cache to media
 828  */
 829 static int pkt_flush_cache(struct pktcdvd_device *pd)
 830 {
 831         struct packet_command cgc;
 832
 833         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 834         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 835         cgc.quiet = 1;
 836
 837         /*
 838          * the IMMED bit -- we default to not setting it, although that
 839          * would allow a much faster close, this is safer
 840          */
 841 #if 0
 842         cgc.cmd[1] = 1 << 1;
 843 #endif
 844         return pkt_generic_packet(pd, &cgc);
 845 }
 846
 847 /*
 848  * speed is given as the normal factor, e.g. 4 for 4x
 849  */
 850 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 851                                 unsigned write_speed, unsigned read_speed)
 852 {
 853         struct packet_command cgc;
 854         struct request_sense sense;
 855         int ret;
 856
 857         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 858         cgc.sense = &sense;
 859         cgc.cmd[0] = GPCMD_SET_SPEED;
 860         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 861         cgc.cmd[3] = read_speed & 0xff;
 862         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 863         cgc.cmd[5] = write_speed & 0xff;
 864
 865         if ((ret = pkt_generic_packet(pd, &cgc)))
 866                 pkt_dump_sense(&cgc);
 867
 868         return ret;
 869 }
 870
 871 /*
 872  * Queue a bio for processing by the low-level CD device. Must be called
 873  * from process context.
 874  */
 875 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 876 {
 877         spin_lock(&pd->iosched.lock);
 878         if (bio_data_dir(bio) == READ) {
 879                 pkt_add_list_last(bio, &pd->iosched.read_queue,
 880                                   &pd->iosched.read_queue_tail);
 881         } else {
 882                 pkt_add_list_last(bio, &pd->iosched.write_queue,
 883                                   &pd->iosched.write_queue_tail);
 884         }
 885         spin_unlock(&pd->iosched.lock);
 886
 887         atomic_set(&pd->iosched.attention, 1);
 888         wake_up(&pd->wqueue);
 889 }
 890
 891 /*
 892  * Process the queued read/write requests. This function handles special
 893  * requirements for CDRW drives:
 894  * - A cache flush command must be inserted before a read request if the
 895  *   previous request was a write.
 896  * - Switching between reading and writing is slow, so don't do it more often
 897  *   than necessary.
 898  * - Optimize for throughput at the expense of latency. This means that streaming
 899  *   writes will never be interrupted by a read, but if the drive has to seek
 900  *   before the next write, switch to reading instead if there are any pending
 901  *   read requests.
 902  * - Set the read speed according to current usage pattern. When only reading
 903  *   from the device, it's best to use the highest possible read speed, but
 904  *   when switching often between reading and writing, it's better to have the
 905  *   same read and write speeds.
 906  */
 907 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 908 {
 909
 910         if (atomic_read(&pd->iosched.attention) == 0)
 911                 return;
 912         atomic_set(&pd->iosched.attention, 0);
 913
 914         for (;;) {
 915                 struct bio *bio;
 916                 int reads_queued, writes_queued;
 917
 918                 spin_lock(&pd->iosched.lock);
 919                 reads_queued = (pd->iosched.read_queue != NULL);
 920                 writes_queued = (pd->iosched.write_queue != NULL);
 921                 spin_unlock(&pd->iosched.lock);
 922
 923                 if (!reads_queued && !writes_queued)
 924                         break;
 925
 926                 if (pd->iosched.writing) {
 927                         int need_write_seek = 1;
 928                         spin_lock(&pd->iosched.lock);
 929                         bio = pd->iosched.write_queue;
 930                         spin_unlock(&pd->iosched.lock);
 931                         if (bio && (bio->bi_sector == pd->iosched.last_write))
 932                                 need_write_seek = 0;
 933                         if (need_write_seek && reads_queued) {
 934                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 935                                         VPRINTK(DRIVER_NAME": write, waiting\n");
 936                                         break;
 937                                 }
 938                                 pkt_flush_cache(pd);
 939                                 pd->iosched.writing = 0;
 940                         }
 941                 } else {
 942                         if (!reads_queued && writes_queued) {
 943                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 944                                         VPRINTK(DRIVER_NAME": read, waiting\n");
 945                                         break;
 946                                 }
 947                                 pd->iosched.writing = 1;
 948                         }
 949                 }
 950
 951                 spin_lock(&pd->iosched.lock);
 952                 if (pd->iosched.writing) {
 953                         bio = pkt_get_list_first(&pd->iosched.write_queue,
 954                                                  &pd->iosched.write_queue_tail);
 955                 } else {
 956                         bio = pkt_get_list_first(&pd->iosched.read_queue,
 957                                                  &pd->iosched.read_queue_tail);
 958                 }
 959                 spin_unlock(&pd->iosched.lock);
 960
 961                 if (!bio)
 962                         continue;
 963
 964                 if (bio_data_dir(bio) == READ)
 965                         pd->iosched.successive_reads += bio->bi_size >> 10;
 966                 else {
 967                         pd->iosched.successive_reads = 0;
 968                         pd->iosched.last_write = bio->bi_sector + bio_sectors(bio);
 969                 }
 970                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 971                         if (pd->read_speed == pd->write_speed) {
 972                                 pd->read_speed = MAX_SPEED;
 973                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 974                         }
 975                 } else {
 976                         if (pd->read_speed != pd->write_speed) {
 977                                 pd->read_speed = pd->write_speed;
 978                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 979                         }
 980                 }
 981
 982                 atomic_inc(&pd->cdrw.pending_bios);
 983                 generic_make_request(bio);
 984         }
 985 }
 986
 987 /*
 988  * Special care is needed if the underlying block device has a small
 989  * max_phys_segments value.
 990  */
 991 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 992 {
 993         if ((pd->settings.size << 9) / CD_FRAMESIZE <= q->max_phys_segments) {
 994                 /*
 995                  * The cdrom device can handle one segment/frame
 996                  */
 997                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 998                 return 0;
 999         } else if ((pd->settings.size << 9) / PAGE_SIZE <= q->max_phys_segments) {
1000                 /*
1001                  * We can handle this case at the expense of some extra memory
1002                  * copies during write operations
1003                  */
1004                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
1005                 return 0;
1006         } else {
1007                 printk(DRIVER_NAME": cdrom max_phys_segments too small\n");
1008                 return -EIO;
1009         }
1010 }
1011
1012 /*
1013  * Copy CD_FRAMESIZE bytes from src_bio into a destination page
1014  */
1015 static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
1016 {
1017         unsigned int copy_size = CD_FRAMESIZE;
1018
1019         while (copy_size > 0) {
1020                 struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
1021                 void *vfrom = kmap_atomic(src_bvl->bv_page, KM_USER0) +
1022                         src_bvl->bv_offset + offs;
1023                 void *vto = page_address(dst_page) + dst_offs;
1024                 int len = min_t(int, copy_size, src_bvl->bv_len - offs);
1025
1026                 BUG_ON(len < 0);
1027                 memcpy(vto, vfrom, len);
1028                 kunmap_atomic(vfrom, KM_USER0);
1029
1030                 seg++;
1031                 offs = 0;
1032                 dst_offs += len;
1033                 copy_size -= len;
1034         }
1035 }
1036
1037 /*
1038  * Copy all data for this packet to pkt->pages[], so that
1039  * a) The number of required segments for the write bio is minimized, which
1040  *    is necessary for some scsi controllers.
1041  * b) The data can be used as cache to avoid read requests if we receive a
1042  *    new write request for the same zone.
1043  */
1044 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
1045 {
1046         int f, p, offs;
1047
1048         /* Copy all data to pkt->pages[] */
1049         p = 0;
1050         offs = 0;
1051         for (f = 0; f < pkt->frames; f++) {
1052                 if (bvec[f].bv_page != pkt->pages[p]) {
1053                         void *vfrom = kmap_atomic(bvec[f].bv_page, KM_USER0) + bvec[f].bv_offset;
1054                         void *vto = page_address(pkt->pages[p]) + offs;
1055                         memcpy(vto, vfrom, CD_FRAMESIZE);
1056                         kunmap_atomic(vfrom, KM_USER0);
1057                         bvec[f].bv_page = pkt->pages[p];
1058                         bvec[f].bv_offset = offs;
1059                 } else {
1060                         BUG_ON(bvec[f].bv_offset != offs);
1061                 }
1062                 offs += CD_FRAMESIZE;
1063                 if (offs >= PAGE_SIZE) {
1064                         offs = 0;
1065                         p++;
1066                 }
1067         }
1068 }
1069
1070 static void pkt_end_io_read(struct bio *bio, int err)
1071 {
1072         struct packet_data *pkt = bio->bi_private;
1073         struct pktcdvd_device *pd = pkt->pd;
1074         BUG_ON(!pd);
1075
1076         VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
1077                 (unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
1078
1079         if (err)
1080                 atomic_inc(&pkt->io_errors);
1081         if (atomic_dec_and_test(&pkt->io_wait)) {
1082                 atomic_inc(&pkt->run_sm);
1083                 wake_up(&pd->wqueue);
1084         }
1085         pkt_bio_finished(pd);
1086 }
1087
1088 static void pkt_end_io_packet_write(struct bio *bio, int err)
1089 {
1090         struct packet_data *pkt = bio->bi_private;
1091         struct pktcdvd_device *pd = pkt->pd;
1092         BUG_ON(!pd);
1093
1094         VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
1095
1096         pd->stats.pkt_ended++;
1097
1098         pkt_bio_finished(pd);
1099         atomic_dec(&pkt->io_wait);
1100         atomic_inc(&pkt->run_sm);
1101         wake_up(&pd->wqueue);
1102 }
1103
1104 /*
1105  * Schedule reads for the holes in a packet
1106  */
1107 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1108 {
1109         int frames_read = 0;
1110         struct bio *bio;
1111         int f;
1112         char written[PACKET_MAX_SIZE];
1113
1114         BUG_ON(!pkt->orig_bios);
1115
1116         atomic_set(&pkt->io_wait, 0);
1117         atomic_set(&pkt->io_errors, 0);
1118
1119         /*
1120          * Figure out which frames we need to read before we can write.
1121          */
1122         memset(written, 0, sizeof(written));
1123         spin_lock(&pkt->lock);
1124         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1125                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1126                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1127                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1128                 BUG_ON(first_frame < 0);
1129                 BUG_ON(first_frame + num_frames > pkt->frames);
1130                 for (f = first_frame; f < first_frame + num_frames; f++)
1131                         written[f] = 1;
1132         }
1133         spin_unlock(&pkt->lock);
1134
1135         if (pkt->cache_valid) {
1136                 VPRINTK("pkt_gather_data: zone %llx cached\n",
1137                         (unsigned long long)pkt->sector);
1138                 goto out_account;
1139         }
1140
1141         /*
1142          * Schedule reads for missing parts of the packet.
1143          */
1144         for (f = 0; f < pkt->frames; f++) {
1145                 struct bio_vec *vec;
1146
1147                 int p, offset;
1148                 if (written[f])
1149                         continue;
1150                 bio = pkt->r_bios[f];
1151                 vec = bio->bi_io_vec;
1152                 bio_init(bio);
1153                 bio->bi_max_vecs = 1;
1154                 bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1155                 bio->bi_bdev = pd->bdev;
1156                 bio->bi_end_io = pkt_end_io_read;
1157                 bio->bi_private = pkt;
1158                 bio->bi_io_vec = vec;
1159                 bio->bi_destructor = pkt_bio_destructor;
1160
1161                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1162                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1163                 VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
1164                         f, pkt->pages[p], offset);
1165                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1166                         BUG();
1167
1168                 atomic_inc(&pkt->io_wait);
1169                 bio->bi_rw = READ;
1170                 pkt_queue_bio(pd, bio);
1171                 frames_read++;
1172         }
1173
1174 out_account:
1175         VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
1176                 frames_read, (unsigned long long)pkt->sector);
1177         pd->stats.pkt_started++;
1178         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1179 }
1180
1181 /*
1182  * Find a packet matching zone, or the least recently used packet if
1183  * there is no match.
1184  */
1185 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1186 {
1187         struct packet_data *pkt;
1188
1189         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1190                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1191                         list_del_init(&pkt->list);
1192                         if (pkt->sector != zone)
1193                                 pkt->cache_valid = 0;
1194                         return pkt;
1195                 }
1196         }
1197         BUG();
1198         return NULL;
1199 }
1200
1201 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1202 {
1203         if (pkt->cache_valid) {
1204                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1205         } else {
1206                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1207         }
1208 }
1209
1210 /*
1211  * recover a failed write, query for relocation if possible
1212  *
1213  * returns 1 if recovery is possible, or 0 if not
1214  *
1215  */
1216 static int pkt_start_recovery(struct packet_data *pkt)
1217 {
1218         /*
1219          * FIXME. We need help from the file system to implement
1220          * recovery handling.
1221          */
1222         return 0;
1223 #if 0
1224         struct request *rq = pkt->rq;
1225         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1226         struct block_device *pkt_bdev;
1227         struct super_block *sb = NULL;
1228         unsigned long old_block, new_block;
1229         sector_t new_sector;
1230
1231         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1232         if (pkt_bdev) {
1233                 sb = get_super(pkt_bdev);
1234                 bdput(pkt_bdev);
1235         }
1236
1237         if (!sb)
1238                 return 0;
1239
1240         if (!sb->s_op || !sb->s_op->relocate_blocks)
1241                 goto out;
1242
1243         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1244         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1245                 goto out;
1246
1247         new_sector = new_block * (CD_FRAMESIZE >> 9);
1248         pkt->sector = new_sector;
1249
1250         pkt->bio->bi_sector = new_sector;
1251         pkt->bio->bi_next = NULL;
1252         pkt->bio->bi_flags = 1 << BIO_UPTODATE;
1253         pkt->bio->bi_idx = 0;
1254
1255         BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
1256         BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
1257         BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
1258         BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
1259         BUG_ON(pkt->bio->bi_private != pkt);
1260
1261         drop_super(sb);
1262         return 1;
1263
1264 out:
1265         drop_super(sb);
1266         return 0;
1267 #endif
1268 }
1269
1270 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1271 {
1272 #if PACKET_DEBUG > 1
1273         static const char *state_name[] = {
1274                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1275         };
1276         enum packet_data_state old_state = pkt->state;
1277         VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
1278                 state_name[old_state], state_name[state]);
1279 #endif
1280         pkt->state = state;
1281 }
1282
1283 /*
1284  * Scan the work queue to see if we can start a new packet.
1285  * returns non-zero if any work was done.
1286  */
1287 static int pkt_handle_queue(struct pktcdvd_device *pd)
1288 {
1289         struct packet_data *pkt, *p;
1290         struct bio *bio = NULL;
1291         sector_t zone = 0; /* Suppress gcc warning */
1292         struct pkt_rb_node *node, *first_node;
1293         struct rb_node *n;
1294         int wakeup;
1295
1296         VPRINTK("handle_queue\n");
1297
1298         atomic_set(&pd->scan_queue, 0);
1299
1300         if (list_empty(&pd->cdrw.pkt_free_list)) {
1301                 VPRINTK("handle_queue: no pkt\n");
1302                 return 0;
1303         }
1304
1305         /*
1306          * Try to find a zone we are not already working on.
1307          */
1308         spin_lock(&pd->lock);
1309         first_node = pkt_rbtree_find(pd, pd->current_sector);
1310         if (!first_node) {
1311                 n = rb_first(&pd->bio_queue);
1312                 if (n)
1313                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1314         }
1315         node = first_node;
1316         while (node) {
1317                 bio = node->bio;
1318                 zone = ZONE(bio->bi_sector, pd);
1319                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1320                         if (p->sector == zone) {
1321                                 bio = NULL;
1322                                 goto try_next_bio;
1323                         }
1324                 }
1325                 break;
1326 try_next_bio:
1327                 node = pkt_rbtree_next(node);
1328                 if (!node) {
1329                         n = rb_first(&pd->bio_queue);
1330                         if (n)
1331                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1332                 }
1333                 if (node == first_node)
1334                         node = NULL;
1335         }
1336         spin_unlock(&pd->lock);
1337         if (!bio) {
1338                 VPRINTK("handle_queue: no bio\n");
1339                 return 0;
1340         }
1341
1342         pkt = pkt_get_packet_data(pd, zone);
1343
1344         pd->current_sector = zone + pd->settings.size;
1345         pkt->sector = zone;
1346         BUG_ON(pkt->frames != pd->settings.size >> 2);
1347         pkt->write_size = 0;
1348
1349         /*
1350          * Scan work queue for bios in the same zone and link them
1351          * to this packet.
1352          */
1353         spin_lock(&pd->lock);
1354         VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
1355         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1356                 bio = node->bio;
1357                 VPRINTK("pkt_handle_queue: found zone=%llx\n",
1358                         (unsigned long long)ZONE(bio->bi_sector, pd));
1359                 if (ZONE(bio->bi_sector, pd) != zone)
1360                         break;
1361                 pkt_rbtree_erase(pd, node);
1362                 spin_lock(&pkt->lock);
1363                 pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
1364                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
1365                 spin_unlock(&pkt->lock);
1366         }
1367         /* check write congestion marks, and if bio_queue_size is
1368            below, wake up any waiters */
1369         wakeup = (pd->write_congestion_on > 0
1370                         && pd->bio_queue_size <= pd->write_congestion_off);
1371         spin_unlock(&pd->lock);
1372         if (wakeup)
1373                 clear_bdi_congested(&pd->disk->queue->backing_dev_info, WRITE);
1374
1375         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1376         pkt_set_state(pkt, PACKET_WAITING_STATE);
1377         atomic_set(&pkt->run_sm, 1);
1378
1379         spin_lock(&pd->cdrw.active_list_lock);
1380         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1381         spin_unlock(&pd->cdrw.active_list_lock);
1382
1383         return 1;
1384 }
1385
1386 /*
1387  * Assemble a bio to write one packet and queue the bio for processing
1388  * by the underlying block device.
1389  */
1390 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1391 {
1392         struct bio *bio;
1393         int f;
1394         int frames_write;
1395         struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1396
1397         for (f = 0; f < pkt->frames; f++) {
1398                 bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1399                 bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1400         }
1401
1402         /*
1403          * Fill-in bvec with data from orig_bios.
1404          */
1405         frames_write = 0;
1406         spin_lock(&pkt->lock);
1407         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1408                 int segment = bio->bi_idx;
1409                 int src_offs = 0;
1410                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1411                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1412                 BUG_ON(first_frame < 0);
1413                 BUG_ON(first_frame + num_frames > pkt->frames);
1414                 for (f = first_frame; f < first_frame + num_frames; f++) {
1415                         struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
1416
1417                         while (src_offs >= src_bvl->bv_len) {
1418                                 src_offs -= src_bvl->bv_len;
1419                                 segment++;
1420                                 BUG_ON(segment >= bio->bi_vcnt);
1421                                 src_bvl = bio_iovec_idx(bio, segment);
1422                         }
1423
1424                         if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
1425                                 bvec[f].bv_page = src_bvl->bv_page;
1426                                 bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
1427                         } else {
1428                                 pkt_copy_bio_data(bio, segment, src_offs,
1429                                                   bvec[f].bv_page, bvec[f].bv_offset);
1430                         }
1431                         src_offs += CD_FRAMESIZE;
1432                         frames_write++;
1433                 }
1434         }
1435         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1436         spin_unlock(&pkt->lock);
1437
1438         VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
1439                 frames_write, (unsigned long long)pkt->sector);
1440         BUG_ON(frames_write != pkt->write_size);
1441
1442         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1443                 pkt_make_local_copy(pkt, bvec);
1444                 pkt->cache_valid = 1;
1445         } else {
1446                 pkt->cache_valid = 0;
1447         }
1448
1449         /* Start the write request */
1450         bio_init(pkt->w_bio);
1451         pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
1452         pkt->w_bio->bi_sector = pkt->sector;
1453         pkt->w_bio->bi_bdev = pd->bdev;
1454         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1455         pkt->w_bio->bi_private = pkt;
1456         pkt->w_bio->bi_io_vec = bvec;
1457         pkt->w_bio->bi_destructor = pkt_bio_destructor;
1458         for (f = 0; f < pkt->frames; f++)
1459                 if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1460                         BUG();
1461         VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
1462
1463         atomic_set(&pkt->io_wait, 1);
1464         pkt->w_bio->bi_rw = WRITE;
1465         pkt_queue_bio(pd, pkt->w_bio);
1466 }
1467
1468 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1469 {
1470         struct bio *bio, *next;
1471
1472         if (!uptodate)
1473                 pkt->cache_valid = 0;
1474
1475         /* Finish all bios corresponding to this packet */
1476         bio = pkt->orig_bios;
1477         while (bio) {
1478                 next = bio->bi_next;
1479                 bio->bi_next = NULL;
1480                 bio_endio(bio, uptodate ? 0 : -EIO);
1481                 bio = next;
1482         }
1483         pkt->orig_bios = pkt->orig_bios_tail = NULL;
1484 }
1485
1486 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1487 {
1488         int uptodate;
1489
1490         VPRINTK("run_state_machine: pkt %d\n", pkt->id);
1491
1492         for (;;) {
1493                 switch (pkt->state) {
1494                 case PACKET_WAITING_STATE:
1495                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1496                                 return;
1497
1498                         pkt->sleep_time = 0;
1499                         pkt_gather_data(pd, pkt);
1500                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1501                         break;
1502
1503                 case PACKET_READ_WAIT_STATE:
1504                         if (atomic_read(&pkt->io_wait) > 0)
1505                                 return;
1506
1507                         if (atomic_read(&pkt->io_errors) > 0) {
1508                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1509                         } else {
1510                                 pkt_start_write(pd, pkt);
1511                         }
1512                         break;
1513
1514                 case PACKET_WRITE_WAIT_STATE:
1515                         if (atomic_read(&pkt->io_wait) > 0)
1516                                 return;
1517
1518                         if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1519                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1520                         } else {
1521                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1522                         }
1523                         break;
1524
1525                 case PACKET_RECOVERY_STATE:
1526                         if (pkt_start_recovery(pkt)) {
1527                                 pkt_start_write(pd, pkt);
1528                         } else {
1529                                 VPRINTK("No recovery possible\n");
1530                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1531                         }
1532                         break;
1533
1534                 case PACKET_FINISHED_STATE:
1535                         uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1536                         pkt_finish_packet(pkt, uptodate);
1537                         return;
1538
1539                 default:
1540                         BUG();
1541                         break;
1542                 }
1543         }
1544 }
1545
1546 static void pkt_handle_packets(struct pktcdvd_device *pd)
1547 {
1548         struct packet_data *pkt, *next;
1549
1550         VPRINTK("pkt_handle_packets\n");
1551
1552         /*
1553          * Run state machine for active packets
1554          */
1555         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1556                 if (atomic_read(&pkt->run_sm) > 0) {
1557                         atomic_set(&pkt->run_sm, 0);
1558                         pkt_run_state_machine(pd, pkt);
1559                 }
1560         }
1561
1562         /*
1563          * Move no longer active packets to the free list
1564          */
1565         spin_lock(&pd->cdrw.active_list_lock);
1566         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1567                 if (pkt->state == PACKET_FINISHED_STATE) {
1568                         list_del(&pkt->list);
1569                         pkt_put_packet_data(pd, pkt);
1570                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1571                         atomic_set(&pd->scan_queue, 1);
1572                 }
1573         }
1574         spin_unlock(&pd->cdrw.active_list_lock);
1575 }
1576
1577 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1578 {
1579         struct packet_data *pkt;
1580         int i;
1581
1582         for (i = 0; i < PACKET_NUM_STATES; i++)
1583                 states[i] = 0;
1584
1585         spin_lock(&pd->cdrw.active_list_lock);
1586         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1587                 states[pkt->state]++;
1588         }
1589         spin_unlock(&pd->cdrw.active_list_lock);
1590 }
1591
1592 /*
1593  * kcdrwd is woken up when writes have been queued for one of our
1594  * registered devices
1595  */
1596 static int kcdrwd(void *foobar)
1597 {
1598         struct pktcdvd_device *pd = foobar;
1599         struct packet_data *pkt;
1600         long min_sleep_time, residue;
1601
1602         set_user_nice(current, -20);
1603         set_freezable();
1604
1605         for (;;) {
1606                 DECLARE_WAITQUEUE(wait, current);
1607
1608                 /*
1609                  * Wait until there is something to do
1610                  */
1611                 add_wait_queue(&pd->wqueue, &wait);
1612                 for (;;) {
1613                         set_current_state(TASK_INTERRUPTIBLE);
1614
1615                         /* Check if we need to run pkt_handle_queue */
1616                         if (atomic_read(&pd->scan_queue) > 0)
1617                                 goto work_to_do;
1618
1619                         /* Check if we need to run the state machine for some packet */
1620                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1621                                 if (atomic_read(&pkt->run_sm) > 0)
1622                                         goto work_to_do;
1623                         }
1624
1625                         /* Check if we need to process the iosched queues */
1626                         if (atomic_read(&pd->iosched.attention) != 0)
1627                                 goto work_to_do;
1628
1629                         /* Otherwise, go to sleep */
1630                         if (PACKET_DEBUG > 1) {
1631                                 int states[PACKET_NUM_STATES];
1632                                 pkt_count_states(pd, states);
1633                                 VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1634                                         states[0], states[1], states[2], states[3],
1635                                         states[4], states[5]);
1636                         }
1637
1638                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1639                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1640                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1641                                         min_sleep_time = pkt->sleep_time;
1642                         }
1643
1644                         generic_unplug_device(bdev_get_queue(pd->bdev));
1645
1646                         VPRINTK("kcdrwd: sleeping\n");
1647                         residue = schedule_timeout(min_sleep_time);
1648                         VPRINTK("kcdrwd: wake up\n");
1649
1650                         /* make swsusp happy with our thread */
1651                         try_to_freeze();
1652
1653                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1654                                 if (!pkt->sleep_time)
1655                                         continue;
1656                                 pkt->sleep_time -= min_sleep_time - residue;
1657                                 if (pkt->sleep_time <= 0) {
1658                                         pkt->sleep_time = 0;
1659                                         atomic_inc(&pkt->run_sm);
1660                                 }
1661                         }
1662
1663                         if (kthread_should_stop())
1664                                 break;
1665                 }
1666 work_to_do:
1667                 set_current_state(TASK_RUNNING);
1668                 remove_wait_queue(&pd->wqueue, &wait);
1669
1670                 if (kthread_should_stop())
1671                         break;
1672
1673                 /*
1674                  * if pkt_handle_queue returns true, we can queue
1675                  * another request.
1676                  */
1677                 while (pkt_handle_queue(pd))
1678                         ;
1679
1680                 /*
1681                  * Handle packet state machine
1682                  */
1683                 pkt_handle_packets(pd);
1684
1685                 /*
1686                  * Handle iosched queues
1687                  */
1688                 pkt_iosched_process_queue(pd);
1689         }
1690
1691         return 0;
1692 }
1693
1694 static void pkt_print_settings(struct pktcdvd_device *pd)
1695 {
1696         printk(DRIVER_NAME": %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
1697         printk("%u blocks, ", pd->settings.size >> 2);
1698         printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
1699 }
1700
1701 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1702 {
1703         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1704
1705         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1706         cgc->cmd[2] = page_code | (page_control << 6);
1707         cgc->cmd[7] = cgc->buflen >> 8;
1708         cgc->cmd[8] = cgc->buflen & 0xff;
1709         cgc->data_direction = CGC_DATA_READ;
1710         return pkt_generic_packet(pd, cgc);
1711 }
1712
1713 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1714 {
1715         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1716         memset(cgc->buffer, 0, 2);
1717         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1718         cgc->cmd[1] = 0x10;             /* PF */
1719         cgc->cmd[7] = cgc->buflen >> 8;
1720         cgc->cmd[8] = cgc->buflen & 0xff;
1721         cgc->data_direction = CGC_DATA_WRITE;
1722         return pkt_generic_packet(pd, cgc);
1723 }
1724
1725 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1726 {
1727         struct packet_command cgc;
1728         int ret;
1729
1730         /* set up command and get the disc info */
1731         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1732         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1733         cgc.cmd[8] = cgc.buflen = 2;
1734         cgc.quiet = 1;
1735
1736         if ((ret = pkt_generic_packet(pd, &cgc)))
1737                 return ret;
1738
1739         /* not all drives have the same disc_info length, so requeue
1740          * packet with the length the drive tells us it can supply
1741          */
1742         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1743                      sizeof(di->disc_information_length);
1744
1745         if (cgc.buflen > sizeof(disc_information))
1746                 cgc.buflen = sizeof(disc_information);
1747
1748         cgc.cmd[8] = cgc.buflen;
1749         return pkt_generic_packet(pd, &cgc);
1750 }
1751
1752 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1753 {
1754         struct packet_command cgc;
1755         int ret;
1756
1757         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1758         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1759         cgc.cmd[1] = type & 3;
1760         cgc.cmd[4] = (track & 0xff00) >> 8;
1761         cgc.cmd[5] = track & 0xff;
1762         cgc.cmd[8] = 8;
1763         cgc.quiet = 1;
1764
1765         if ((ret = pkt_generic_packet(pd, &cgc)))
1766                 return ret;
1767
1768         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1769                      sizeof(ti->track_information_length);
1770
1771         if (cgc.buflen > sizeof(track_information))
1772                 cgc.buflen = sizeof(track_information);
1773
1774         cgc.cmd[8] = cgc.buflen;
1775         return pkt_generic_packet(pd, &cgc);
1776 }
1777
1778 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1779                                                 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 noinline_for_stack 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 noinline_for_stack 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 noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
2075                                                 int set)
2076 {
2077         struct packet_command cgc;
2078         struct request_sense sense;
2079         unsigned char buf[64];
2080         int ret;
2081
2082         memset(buf, 0, sizeof(buf));
2083         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
2084         cgc.sense = &sense;
2085         cgc.buflen = pd->mode_offset + 12;
2086
2087         /*
2088          * caching mode page might not be there, so quiet this command
2089          */
2090         cgc.quiet = 1;
2091
2092         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
2093                 return ret;
2094
2095         buf[pd->mode_offset + 10] |= (!!set << 2);
2096
2097         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
2098         ret = pkt_mode_select(pd, &cgc);
2099         if (ret) {
2100                 printk(DRIVER_NAME": write caching control failed\n");
2101                 pkt_dump_sense(&cgc);
2102         } else if (!ret && set)
2103                 printk(DRIVER_NAME": enabled write caching on %s\n", pd->name);
2104         return ret;
2105 }
2106
2107 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
2108 {
2109         struct packet_command cgc;
2110
2111         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2112         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
2113         cgc.cmd[4] = lockflag ? 1 : 0;
2114         return pkt_generic_packet(pd, &cgc);
2115 }
2116
2117 /*
2118  * Returns drive maximum write speed
2119  */
2120 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
2121                                                 unsigned *write_speed)
2122 {
2123         struct packet_command cgc;
2124         struct request_sense sense;
2125         unsigned char buf[256+18];
2126         unsigned char *cap_buf;
2127         int ret, offset;
2128
2129         memset(buf, 0, sizeof(buf));
2130         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
2131         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
2132         cgc.sense = &sense;
2133
2134         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2135         if (ret) {
2136                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2137                              sizeof(struct mode_page_header);
2138                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2139                 if (ret) {
2140                         pkt_dump_sense(&cgc);
2141                         return ret;
2142                 }
2143         }
2144
2145         offset = 20;                        /* Obsoleted field, used by older drives */
2146         if (cap_buf[1] >= 28)
2147                 offset = 28;                /* Current write speed selected */
2148         if (cap_buf[1] >= 30) {
2149                 /* If the drive reports at least one "Logical Unit Write
2150                  * Speed Performance Descriptor Block", use the information
2151                  * in the first block. (contains the highest speed)
2152                  */
2153                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2154                 if (num_spdb > 0)
2155                         offset = 34;
2156         }
2157
2158         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2159         return 0;
2160 }
2161
2162 /* These tables from cdrecord - I don't have orange book */
2163 /* standard speed CD-RW (1-4x) */
2164 static char clv_to_speed[16] = {
2165         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2166            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2167 };
2168 /* high speed CD-RW (-10x) */
2169 static char hs_clv_to_speed[16] = {
2170         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2171            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2172 };
2173 /* ultra high speed CD-RW */
2174 static char us_clv_to_speed[16] = {
2175         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2176            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2177 };
2178
2179 /*
2180  * reads the maximum media speed from ATIP
2181  */
2182 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2183                                                 unsigned *speed)
2184 {
2185         struct packet_command cgc;
2186         struct request_sense sense;
2187         unsigned char buf[64];
2188         unsigned int size, st, sp;
2189         int ret;
2190
2191         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2192         cgc.sense = &sense;
2193         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2194         cgc.cmd[1] = 2;
2195         cgc.cmd[2] = 4; /* READ ATIP */
2196         cgc.cmd[8] = 2;
2197         ret = pkt_generic_packet(pd, &cgc);
2198         if (ret) {
2199                 pkt_dump_sense(&cgc);
2200                 return ret;
2201         }
2202         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2203         if (size > sizeof(buf))
2204                 size = sizeof(buf);
2205
2206         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2207         cgc.sense = &sense;
2208         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2209         cgc.cmd[1] = 2;
2210         cgc.cmd[2] = 4;
2211         cgc.cmd[8] = size;
2212         ret = pkt_generic_packet(pd, &cgc);
2213         if (ret) {
2214                 pkt_dump_sense(&cgc);
2215                 return ret;
2216         }
2217
2218         if (!(buf[6] & 0x40)) {
2219                 printk(DRIVER_NAME": Disc type is not CD-RW\n");
2220                 return 1;
2221         }
2222         if (!(buf[6] & 0x4)) {
2223                 printk(DRIVER_NAME": A1 values on media are not valid, maybe not CDRW?\n");
2224                 return 1;
2225         }
2226
2227         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2228
2229         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2230
2231         /* Info from cdrecord */
2232         switch (st) {
2233                 case 0: /* standard speed */
2234                         *speed = clv_to_speed[sp];
2235                         break;
2236                 case 1: /* high speed */
2237                         *speed = hs_clv_to_speed[sp];
2238                         break;
2239                 case 2: /* ultra high speed */
2240                         *speed = us_clv_to_speed[sp];
2241                         break;
2242                 default:
2243                         printk(DRIVER_NAME": Unknown disc sub-type %d\n",st);
2244                         return 1;
2245         }
2246         if (*speed) {
2247                 printk(DRIVER_NAME": Max. media speed: %d\n",*speed);
2248                 return 0;
2249         } else {
2250                 printk(DRIVER_NAME": Unknown speed %d for sub-type %d\n",sp,st);
2251                 return 1;
2252         }
2253 }
2254
2255 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2256 {
2257         struct packet_command cgc;
2258         struct request_sense sense;
2259         int ret;
2260
2261         VPRINTK(DRIVER_NAME": Performing OPC\n");
2262
2263         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2264         cgc.sense = &sense;
2265         cgc.timeout = 60*HZ;
2266         cgc.cmd[0] = GPCMD_SEND_OPC;
2267         cgc.cmd[1] = 1;
2268         if ((ret = pkt_generic_packet(pd, &cgc)))
2269                 pkt_dump_sense(&cgc);
2270         return ret;
2271 }
2272
2273 static int pkt_open_write(struct pktcdvd_device *pd)
2274 {
2275         int ret;
2276         unsigned int write_speed, media_write_speed, read_speed;
2277
2278         if ((ret = pkt_probe_settings(pd))) {
2279                 VPRINTK(DRIVER_NAME": %s failed probe\n", pd->name);
2280                 return ret;
2281         }
2282
2283         if ((ret = pkt_set_write_settings(pd))) {
2284                 DPRINTK(DRIVER_NAME": %s failed saving write settings\n", pd->name);
2285                 return -EIO;
2286         }
2287
2288         pkt_write_caching(pd, USE_WCACHING);
2289
2290         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2291                 write_speed = 16 * 177;
2292         switch (pd->mmc3_profile) {
2293                 case 0x13: /* DVD-RW */
2294                 case 0x1a: /* DVD+RW */
2295                 case 0x12: /* DVD-RAM */
2296                         DPRINTK(DRIVER_NAME": write speed %ukB/s\n", write_speed);
2297                         break;
2298                 default:
2299                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2300                                 media_write_speed = 16;
2301                         write_speed = min(write_speed, media_write_speed * 177);
2302                         DPRINTK(DRIVER_NAME": write speed %ux\n", write_speed / 176);
2303                         break;
2304         }
2305         read_speed = write_speed;
2306
2307         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2308                 DPRINTK(DRIVER_NAME": %s couldn't set write speed\n", pd->name);
2309                 return -EIO;
2310         }
2311         pd->write_speed = write_speed;
2312         pd->read_speed = read_speed;
2313
2314         if ((ret = pkt_perform_opc(pd))) {
2315                 DPRINTK(DRIVER_NAME": %s Optimum Power Calibration failed\n", pd->name);
2316         }
2317
2318         return 0;
2319 }
2320
2321 /*
2322  * called at open time.
2323  */
2324 static int pkt_open_dev(struct pktcdvd_device *pd, int write)
2325 {
2326         int ret;
2327         long lba;
2328         struct request_queue *q;
2329
2330         /*
2331          * We need to re-open the cdrom device without O_NONBLOCK to be able
2332          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2333          * so bdget() can't fail.
2334          */
2335         bdget(pd->bdev->bd_dev);
2336         if ((ret = blkdev_get(pd->bdev, FMODE_READ, O_RDONLY)))
2337                 goto out;
2338
2339         if ((ret = bd_claim(pd->bdev, pd)))
2340                 goto out_putdev;
2341
2342         if ((ret = pkt_get_last_written(pd, &lba))) {
2343                 printk(DRIVER_NAME": pkt_get_last_written failed\n");
2344                 goto out_unclaim;
2345         }
2346
2347         set_capacity(pd->disk, lba << 2);
2348         set_capacity(pd->bdev->bd_disk, lba << 2);
2349         bd_set_size(pd->bdev, (loff_t)lba << 11);
2350
2351         q = bdev_get_queue(pd->bdev);
2352         if (write) {
2353                 if ((ret = pkt_open_write(pd)))
2354                         goto out_unclaim;
2355                 /*
2356                  * Some CDRW drives can not handle writes larger than one packet,
2357                  * even if the size is a multiple of the packet size.
2358                  */
2359                 spin_lock_irq(q->queue_lock);
2360                 blk_queue_max_sectors(q, pd->settings.size);
2361                 spin_unlock_irq(q->queue_lock);
2362                 set_bit(PACKET_WRITABLE, &pd->flags);
2363         } else {
2364                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2365                 clear_bit(PACKET_WRITABLE, &pd->flags);
2366         }
2367
2368         if ((ret = pkt_set_segment_merging(pd, q)))
2369                 goto out_unclaim;
2370
2371         if (write) {
2372                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2373                         printk(DRIVER_NAME": not enough memory for buffers\n");
2374                         ret = -ENOMEM;
2375                         goto out_unclaim;
2376                 }
2377                 printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
2378         }
2379
2380         return 0;
2381
2382 out_unclaim:
2383         bd_release(pd->bdev);
2384 out_putdev:
2385         blkdev_put(pd->bdev);
2386 out:
2387         return ret;
2388 }
2389
2390 /*
2391  * called when the device is closed. makes sure that the device flushes
2392  * the internal cache before we close.
2393  */
2394 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2395 {
2396         if (flush && pkt_flush_cache(pd))
2397                 DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
2398
2399         pkt_lock_door(pd, 0);
2400
2401         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2402         bd_release(pd->bdev);
2403         blkdev_put(pd->bdev);
2404
2405         pkt_shrink_pktlist(pd);
2406 }
2407
2408 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
2409 {
2410         if (dev_minor >= MAX_WRITERS)
2411                 return NULL;
2412         return pkt_devs[dev_minor];
2413 }
2414
2415 static int pkt_open(struct inode *inode, struct file *file)
2416 {
2417         struct pktcdvd_device *pd = NULL;
2418         int ret;
2419
2420         VPRINTK(DRIVER_NAME": entering open\n");
2421
2422         mutex_lock(&ctl_mutex);
2423         pd = pkt_find_dev_from_minor(iminor(inode));
2424         if (!pd) {
2425                 ret = -ENODEV;
2426                 goto out;
2427         }
2428         BUG_ON(pd->refcnt < 0);
2429
2430         pd->refcnt++;
2431         if (pd->refcnt > 1) {
2432                 if ((file->f_mode & FMODE_WRITE) &&
2433                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2434                         ret = -EBUSY;
2435                         goto out_dec;
2436                 }
2437         } else {
2438                 ret = pkt_open_dev(pd, file->f_mode & FMODE_WRITE);
2439                 if (ret)
2440                         goto out_dec;
2441                 /*
2442                  * needed here as well, since ext2 (among others) may change
2443                  * the blocksize at mount time
2444                  */
2445                 set_blocksize(inode->i_bdev, CD_FRAMESIZE);
2446         }
2447
2448         mutex_unlock(&ctl_mutex);
2449         return 0;
2450
2451 out_dec:
2452         pd->refcnt--;
2453 out:
2454         VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
2455         mutex_unlock(&ctl_mutex);
2456         return ret;
2457 }
2458
2459 static int pkt_close(struct inode *inode, struct file *file)
2460 {
2461         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2462         int ret = 0;
2463
2464         mutex_lock(&ctl_mutex);
2465         pd->refcnt--;
2466         BUG_ON(pd->refcnt < 0);
2467         if (pd->refcnt == 0) {
2468                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2469                 pkt_release_dev(pd, flush);
2470         }
2471         mutex_unlock(&ctl_mutex);
2472         return ret;
2473 }
2474
2475
2476 static void pkt_end_io_read_cloned(struct bio *bio, int err)
2477 {
2478         struct packet_stacked_data *psd = bio->bi_private;
2479         struct pktcdvd_device *pd = psd->pd;
2480
2481         bio_put(bio);
2482         bio_endio(psd->bio, err);
2483         mempool_free(psd, psd_pool);
2484         pkt_bio_finished(pd);
2485 }
2486
2487 static int pkt_make_request(struct request_queue *q, struct bio *bio)
2488 {
2489         struct pktcdvd_device *pd;
2490         char b[BDEVNAME_SIZE];
2491         sector_t zone;
2492         struct packet_data *pkt;
2493         int was_empty, blocked_bio;
2494         struct pkt_rb_node *node;
2495
2496         pd = q->queuedata;
2497         if (!pd) {
2498                 printk(DRIVER_NAME": %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
2499                 goto end_io;
2500         }
2501
2502         /*
2503          * Clone READ bios so we can have our own bi_end_io callback.
2504          */
2505         if (bio_data_dir(bio) == READ) {
2506                 struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2507                 struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2508
2509                 psd->pd = pd;
2510                 psd->bio = bio;
2511                 cloned_bio->bi_bdev = pd->bdev;
2512                 cloned_bio->bi_private = psd;
2513                 cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2514                 pd->stats.secs_r += bio->bi_size >> 9;
2515                 pkt_queue_bio(pd, cloned_bio);
2516                 return 0;
2517         }
2518
2519         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2520                 printk(DRIVER_NAME": WRITE for ro device %s (%llu)\n",
2521                         pd->name, (unsigned long long)bio->bi_sector);
2522                 goto end_io;
2523         }
2524
2525         if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
2526                 printk(DRIVER_NAME": wrong bio size\n");
2527                 goto end_io;
2528         }
2529
2530         blk_queue_bounce(q, &bio);
2531
2532         zone = ZONE(bio->bi_sector, pd);
2533         VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
2534                 (unsigned long long)bio->bi_sector,
2535                 (unsigned long long)(bio->bi_sector + bio_sectors(bio)));
2536
2537         /* Check if we have to split the bio */
2538         {
2539                 struct bio_pair *bp;
2540                 sector_t last_zone;
2541                 int first_sectors;
2542
2543                 last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
2544                 if (last_zone != zone) {
2545                         BUG_ON(last_zone != zone + pd->settings.size);
2546                         first_sectors = last_zone - bio->bi_sector;
2547                         bp = bio_split(bio, bio_split_pool, first_sectors);
2548                         BUG_ON(!bp);
2549                         pkt_make_request(q, &bp->bio1);
2550                         pkt_make_request(q, &bp->bio2);
2551                         bio_pair_release(bp);
2552                         return 0;
2553                 }
2554         }
2555
2556         /*
2557          * If we find a matching packet in state WAITING or READ_WAIT, we can
2558          * just append this bio to that packet.
2559          */
2560         spin_lock(&pd->cdrw.active_list_lock);
2561         blocked_bio = 0;
2562         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2563                 if (pkt->sector == zone) {
2564                         spin_lock(&pkt->lock);
2565                         if ((pkt->state == PACKET_WAITING_STATE) ||
2566                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2567                                 pkt_add_list_last(bio, &pkt->orig_bios,
2568                                                   &pkt->orig_bios_tail);
2569                                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
2570                                 if ((pkt->write_size >= pkt->frames) &&
2571                                     (pkt->state == PACKET_WAITING_STATE)) {
2572                                         atomic_inc(&pkt->run_sm);
2573                                         wake_up(&pd->wqueue);
2574                                 }
2575                                 spin_unlock(&pkt->lock);
2576                                 spin_unlock(&pd->cdrw.active_list_lock);
2577                                 return 0;
2578                         } else {
2579                                 blocked_bio = 1;
2580                         }
2581                         spin_unlock(&pkt->lock);
2582                 }
2583         }
2584         spin_unlock(&pd->cdrw.active_list_lock);
2585
2586         /*
2587          * Test if there is enough room left in the bio work queue
2588          * (queue size >= congestion on mark).
2589          * If not, wait till the work queue size is below the congestion off mark.
2590          */
2591         spin_lock(&pd->lock);
2592         if (pd->write_congestion_on > 0
2593             && pd->bio_queue_size >= pd->write_congestion_on) {
2594                 set_bdi_congested(&q->backing_dev_info, WRITE);
2595                 do {
2596                         spin_unlock(&pd->lock);
2597                         congestion_wait(WRITE, HZ);
2598                         spin_lock(&pd->lock);
2599                 } while(pd->bio_queue_size > pd->write_congestion_off);
2600         }
2601         spin_unlock(&pd->lock);
2602
2603         /*
2604          * No matching packet found. Store the bio in the work queue.
2605          */
2606         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2607         node->bio = bio;
2608         spin_lock(&pd->lock);
2609         BUG_ON(pd->bio_queue_size < 0);
2610         was_empty = (pd->bio_queue_size == 0);
2611         pkt_rbtree_insert(pd, node);
2612         spin_unlock(&pd->lock);
2613
2614         /*
2615          * Wake up the worker thread.
2616          */
2617         atomic_set(&pd->scan_queue, 1);
2618         if (was_empty) {
2619                 /* This wake_up is required for correct operation */
2620                 wake_up(&pd->wqueue);
2621         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2622                 /*
2623                  * This wake up is not required for correct operation,
2624                  * but improves performance in some cases.
2625                  */
2626                 wake_up(&pd->wqueue);
2627         }
2628         return 0;
2629 end_io:
2630         bio_io_error(bio);
2631         return 0;
2632 }
2633
2634
2635
2636 static int pkt_merge_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *bvec)
2637 {
2638         struct pktcdvd_device *pd = q->queuedata;
2639         sector_t zone = ZONE(bio->bi_sector, pd);
2640         int used = ((bio->bi_sector - zone) << 9) + bio->bi_size;
2641         int remaining = (pd->settings.size << 9) - used;
2642         int remaining2;
2643
2644         /*
2645          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2646          * boundary, pkt_make_request() will split the bio.
2647          */
2648         remaining2 = PAGE_SIZE - bio->bi_size;
2649         remaining = max(remaining, remaining2);
2650
2651         BUG_ON(remaining < 0);
2652         return remaining;
2653 }
2654
2655 static void pkt_init_queue(struct pktcdvd_device *pd)
2656 {
2657         struct request_queue *q = pd->disk->queue;
2658
2659         blk_queue_make_request(q, pkt_make_request);
2660         blk_queue_hardsect_size(q, CD_FRAMESIZE);
2661         blk_queue_max_sectors(q, PACKET_MAX_SECTORS);
2662         blk_queue_merge_bvec(q, pkt_merge_bvec);
2663         q->queuedata = pd;
2664 }
2665
2666 static int pkt_seq_show(struct seq_file *m, void *p)
2667 {
2668         struct pktcdvd_device *pd = m->private;
2669         char *msg;
2670         char bdev_buf[BDEVNAME_SIZE];
2671         int states[PACKET_NUM_STATES];
2672
2673         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2674                    bdevname(pd->bdev, bdev_buf));
2675
2676         seq_printf(m, "\nSettings:\n");
2677         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2678
2679         if (pd->settings.write_type == 0)
2680                 msg = "Packet";
2681         else
2682                 msg = "Unknown";
2683         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2684
2685         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2686         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2687
2688         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2689
2690         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2691                 msg = "Mode 1";
2692         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2693                 msg = "Mode 2";
2694         else
2695                 msg = "Unknown";
2696         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2697
2698         seq_printf(m, "\nStatistics:\n");
2699         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2700         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2701         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2702         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2703         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2704
2705         seq_printf(m, "\nMisc:\n");
2706         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2707         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2708         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2709         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2710         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2711         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2712
2713         seq_printf(m, "\nQueue state:\n");
2714         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2715         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2716         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2717
2718         pkt_count_states(pd, states);
2719         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2720                    states[0], states[1], states[2], states[3], states[4], states[5]);
2721
2722         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2723                         pd->write_congestion_off,
2724                         pd->write_congestion_on);
2725         return 0;
2726 }
2727
2728 static int pkt_seq_open(struct inode *inode, struct file *file)
2729 {
2730         return single_open(file, pkt_seq_show, PDE(inode)->data);
2731 }
2732
2733 static const struct file_operations pkt_proc_fops = {
2734         .open   = pkt_seq_open,
2735         .read   = seq_read,
2736         .llseek = seq_lseek,
2737         .release = single_release
2738 };
2739
2740 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2741 {
2742         int i;
2743         int ret = 0;
2744         char b[BDEVNAME_SIZE];
2745         struct block_device *bdev;
2746
2747         if (pd->pkt_dev == dev) {
2748                 printk(DRIVER_NAME": Recursive setup not allowed\n");
2749                 return -EBUSY;
2750         }
2751         for (i = 0; i < MAX_WRITERS; i++) {
2752                 struct pktcdvd_device *pd2 = pkt_devs[i];
2753                 if (!pd2)
2754                         continue;
2755                 if (pd2->bdev->bd_dev == dev) {
2756                         printk(DRIVER_NAME": %s already setup\n", bdevname(pd2->bdev, b));
2757                         return -EBUSY;
2758                 }
2759                 if (pd2->pkt_dev == dev) {
2760                         printk(DRIVER_NAME": Can't chain pktcdvd devices\n");
2761                         return -EBUSY;
2762                 }
2763         }
2764
2765         bdev = bdget(dev);
2766         if (!bdev)
2767                 return -ENOMEM;
2768         ret = blkdev_get(bdev, FMODE_READ, O_RDONLY | O_NONBLOCK);
2769         if (ret)
2770                 return ret;
2771
2772         /* This is safe, since we have a reference from open(). */
2773         __module_get(THIS_MODULE);
2774
2775         pd->bdev = bdev;
2776         set_blocksize(bdev, CD_FRAMESIZE);
2777
2778         pkt_init_queue(pd);
2779
2780         atomic_set(&pd->cdrw.pending_bios, 0);
2781         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2782         if (IS_ERR(pd->cdrw.thread)) {
2783                 printk(DRIVER_NAME": can't start kernel thread\n");
2784                 ret = -ENOMEM;
2785                 goto out_mem;
2786         }
2787
2788         proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2789         DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
2790         return 0;
2791
2792 out_mem:
2793         blkdev_put(bdev);
2794         /* This is safe: open() is still holding a reference. */
2795         module_put(THIS_MODULE);
2796         return ret;
2797 }
2798
2799 static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
2800 {
2801         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2802
2803         VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd, imajor(inode), iminor(inode));
2804
2805         switch (cmd) {
2806         /*
2807          * forward selected CDROM ioctls to CD-ROM, for UDF
2808          */
2809         case CDROMMULTISESSION:
2810         case CDROMREADTOCENTRY:
2811         case CDROM_LAST_WRITTEN:
2812         case CDROM_SEND_PACKET:
2813         case SCSI_IOCTL_SEND_COMMAND:
2814                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2815
2816         case CDROMEJECT:
2817                 /*
2818                  * The door gets locked when the device is opened, so we
2819                  * have to unlock it or else the eject command fails.
2820                  */
2821                 if (pd->refcnt == 1)
2822                         pkt_lock_door(pd, 0);
2823                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2824
2825         default:
2826                 VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, cmd);
2827                 return -ENOTTY;
2828         }
2829
2830         return 0;
2831 }
2832
2833 static int pkt_media_changed(struct gendisk *disk)
2834 {
2835         struct pktcdvd_device *pd = disk->private_data;
2836         struct gendisk *attached_disk;
2837
2838         if (!pd)
2839                 return 0;
2840         if (!pd->bdev)
2841                 return 0;
2842         attached_disk = pd->bdev->bd_disk;
2843         if (!attached_disk)
2844                 return 0;
2845         return attached_disk->fops->media_changed(attached_disk);
2846 }
2847
2848 static struct block_device_operations pktcdvd_ops = {
2849         .owner =                THIS_MODULE,
2850         .open =                 pkt_open,
2851         .release =              pkt_close,
2852         .ioctl =                pkt_ioctl,
2853         .media_changed =        pkt_media_changed,
2854 };
2855
2856 /*
2857  * Set up mapping from pktcdvd device to CD-ROM device.
2858  */
2859 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2860 {
2861         int idx;
2862         int ret = -ENOMEM;
2863         struct pktcdvd_device *pd;
2864         struct gendisk *disk;
2865
2866         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2867
2868         for (idx = 0; idx < MAX_WRITERS; idx++)
2869                 if (!pkt_devs[idx])
2870                         break;
2871         if (idx == MAX_WRITERS) {
2872                 printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
2873                 ret = -EBUSY;
2874                 goto out_mutex;
2875         }
2876
2877         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2878         if (!pd)
2879                 goto out_mutex;
2880
2881         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2882                                                   sizeof(struct pkt_rb_node));
2883         if (!pd->rb_pool)
2884                 goto out_mem;
2885
2886         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2887         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2888         spin_lock_init(&pd->cdrw.active_list_lock);
2889
2890         spin_lock_init(&pd->lock);
2891         spin_lock_init(&pd->iosched.lock);
2892         sprintf(pd->name, DRIVER_NAME"%d", idx);
2893         init_waitqueue_head(&pd->wqueue);
2894         pd->bio_queue = RB_ROOT;
2895
2896         pd->write_congestion_on  = write_congestion_on;
2897         pd->write_congestion_off = write_congestion_off;
2898
2899         disk = alloc_disk(1);
2900         if (!disk)
2901                 goto out_mem;
2902         pd->disk = disk;
2903         disk->major = pktdev_major;
2904         disk->first_minor = idx;
2905         disk->fops = &pktcdvd_ops;
2906         disk->flags = GENHD_FL_REMOVABLE;
2907         strcpy(disk->disk_name, pd->name);
2908         disk->private_data = pd;
2909         disk->queue = blk_alloc_queue(GFP_KERNEL);
2910         if (!disk->queue)
2911                 goto out_mem2;
2912
2913         pd->pkt_dev = MKDEV(disk->major, disk->first_minor);
2914         ret = pkt_new_dev(pd, dev);
2915         if (ret)
2916                 goto out_new_dev;
2917
2918         add_disk(disk);
2919
2920         pkt_sysfs_dev_new(pd);
2921         pkt_debugfs_dev_new(pd);
2922
2923         pkt_devs[idx] = pd;
2924         if (pkt_dev)
2925                 *pkt_dev = pd->pkt_dev;
2926
2927         mutex_unlock(&ctl_mutex);
2928         return 0;
2929
2930 out_new_dev:
2931         blk_cleanup_queue(disk->queue);
2932 out_mem2:
2933         put_disk(disk);
2934 out_mem:
2935         if (pd->rb_pool)
2936                 mempool_destroy(pd->rb_pool);
2937         kfree(pd);
2938 out_mutex:
2939         mutex_unlock(&ctl_mutex);
2940         printk(DRIVER_NAME": setup of pktcdvd device failed\n");
2941         return ret;
2942 }
2943
2944 /*
2945  * Tear down mapping from pktcdvd device to CD-ROM device.
2946  */
2947 static int pkt_remove_dev(dev_t pkt_dev)
2948 {
2949         struct pktcdvd_device *pd;
2950         int idx;
2951         int ret = 0;
2952
2953         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2954
2955         for (idx = 0; idx < MAX_WRITERS; idx++) {
2956                 pd = pkt_devs[idx];
2957                 if (pd && (pd->pkt_dev == pkt_dev))
2958                         break;
2959         }
2960         if (idx == MAX_WRITERS) {
2961                 DPRINTK(DRIVER_NAME": dev not setup\n");
2962                 ret = -ENXIO;
2963                 goto out;
2964         }
2965
2966         if (pd->refcnt > 0) {
2967                 ret = -EBUSY;
2968                 goto out;
2969         }
2970         if (!IS_ERR(pd->cdrw.thread))
2971                 kthread_stop(pd->cdrw.thread);
2972
2973         pkt_devs[idx] = NULL;
2974
2975         pkt_debugfs_dev_remove(pd);
2976         pkt_sysfs_dev_remove(pd);
2977
2978         blkdev_put(pd->bdev);
2979
2980         remove_proc_entry(pd->name, pkt_proc);
2981         DPRINTK(DRIVER_NAME": writer %s unmapped\n", pd->name);
2982
2983         del_gendisk(pd->disk);
2984         blk_cleanup_queue(pd->disk->queue);
2985         put_disk(pd->disk);
2986
2987         mempool_destroy(pd->rb_pool);
2988         kfree(pd);
2989
2990         /* This is safe: open() is still holding a reference. */
2991         module_put(THIS_MODULE);
2992
2993 out:
2994         mutex_unlock(&ctl_mutex);
2995         return ret;
2996 }
2997
2998 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2999 {
3000         struct pktcdvd_device *pd;
3001
3002         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3003
3004         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
3005         if (pd) {
3006                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
3007                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
3008         } else {
3009                 ctrl_cmd->dev = 0;
3010                 ctrl_cmd->pkt_dev = 0;
3011         }
3012         ctrl_cmd->num_devices = MAX_WRITERS;
3013
3014         mutex_unlock(&ctl_mutex);
3015 }
3016
3017 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
3018 {
3019         void __user *argp = (void __user *)arg;
3020         struct pkt_ctrl_command ctrl_cmd;
3021         int ret = 0;
3022         dev_t pkt_dev = 0;
3023
3024         if (cmd != PACKET_CTRL_CMD)
3025                 return -ENOTTY;
3026
3027         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
3028                 return -EFAULT;
3029
3030         switch (ctrl_cmd.command) {
3031         case PKT_CTRL_CMD_SETUP:
3032                 if (!capable(CAP_SYS_ADMIN))
3033                         return -EPERM;
3034                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
3035                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
3036                 break;
3037         case PKT_CTRL_CMD_TEARDOWN:
3038                 if (!capable(CAP_SYS_ADMIN))
3039                         return -EPERM;
3040                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
3041                 break;
3042         case PKT_CTRL_CMD_STATUS:
3043                 pkt_get_status(&ctrl_cmd);
3044                 break;
3045         default:
3046                 return -ENOTTY;
3047         }
3048
3049         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
3050                 return -EFAULT;
3051         return ret;
3052 }
3053
3054
3055 static const struct file_operations pkt_ctl_fops = {
3056         .ioctl   = pkt_ctl_ioctl,
3057         .owner   = THIS_MODULE,
3058 };
3059
3060 static struct miscdevice pkt_misc = {
3061         .minor          = MISC_DYNAMIC_MINOR,
3062         .name           = DRIVER_NAME,
3063         .fops           = &pkt_ctl_fops
3064 };
3065
3066 static int __init pkt_init(void)
3067 {
3068         int ret;
3069
3070         mutex_init(&ctl_mutex);
3071
3072         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
3073                                         sizeof(struct packet_stacked_data));
3074         if (!psd_pool)
3075                 return -ENOMEM;
3076
3077         ret = register_blkdev(pktdev_major, DRIVER_NAME);
3078         if (ret < 0) {
3079                 printk(DRIVER_NAME": Unable to register block device\n");
3080                 goto out2;
3081         }
3082         if (!pktdev_major)
3083                 pktdev_major = ret;
3084
3085         ret = pkt_sysfs_init();
3086         if (ret)
3087                 goto out;
3088
3089         pkt_debugfs_init();
3090
3091         ret = misc_register(&pkt_misc);
3092         if (ret) {
3093                 printk(DRIVER_NAME": Unable to register misc device\n");
3094                 goto out_misc;
3095         }
3096
3097         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
3098
3099         return 0;
3100
3101 out_misc:
3102         pkt_debugfs_cleanup();
3103         pkt_sysfs_cleanup();
3104 out:
3105         unregister_blkdev(pktdev_major, DRIVER_NAME);
3106 out2:
3107         mempool_destroy(psd_pool);
3108         return ret;
3109 }
3110
3111 static void __exit pkt_exit(void)
3112 {
3113         remove_proc_entry("driver/"DRIVER_NAME, NULL);
3114         misc_deregister(&pkt_misc);
3115
3116         pkt_debugfs_cleanup();
3117         pkt_sysfs_cleanup();
3118
3119         unregister_blkdev(pktdev_major, DRIVER_NAME);
3120         mempool_destroy(psd_pool);
3121 }
3122
3123 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3124 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3125 MODULE_LICENSE("GPL");
3126
3127 module_init(pkt_init);
3128 module_exit(pkt_exit);