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