drivers/block/pktcdvd.c

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   4  * Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
   5  *
   6  * May be copied or modified under the terms of the GNU General Public
   7  * License.  See linux/COPYING for more information.
   8  *
   9  * Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
  10  * DVD-RAM devices.
  11  *
  12  * Theory of operation:
  13  *
  14  * At the lowest level, there is the standard driver for the CD/DVD device,
  15  * typically ide-cd.c or sr.c. This driver can handle read and write requests,
  16  * but it doesn't know anything about the special restrictions that apply to
  17  * packet writing. One restriction is that write requests must be aligned to
  18  * packet boundaries on the physical media, and the size of a write request
  19  * must be equal to the packet size. Another restriction is that a
  20  * GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
  21  * command, if the previous command was a write.
  22  *
  23  * The purpose of the packet writing driver is to hide these restrictions from
  24  * higher layers, such as file systems, and present a block device that can be
  25  * randomly read and written using 2kB-sized blocks.
  26  *
  27  * The lowest layer in the packet writing driver is the packet I/O scheduler.
  28  * Its data is defined by the struct packet_iosched and includes two bio
  29  * queues with pending read and write requests. These queues are processed
  30  * by the pkt_iosched_process_queue() function. The write requests in this
  31  * queue are already properly aligned and sized. This layer is responsible for
  32  * issuing the flush cache commands and scheduling the I/O in a good order.
  33  *
  34  * The next layer transforms unaligned write requests to aligned writes. This
  35  * transformation requires reading missing pieces of data from the underlying
  36  * block device, assembling the pieces to full packets and queuing them to the
  37  * packet I/O scheduler.
  38  *
  39  * At the top layer there is a custom make_request_fn function that forwards
  40  * read requests directly to the iosched queue and puts write requests in the
  41  * unaligned write queue. A kernel thread performs the necessary read
  42  * gathering to convert the unaligned writes to aligned writes and then feeds
  43  * them to the packet I/O scheduler.
  44  *
  45  *************************************************************************/
  46
  47 #include <linux/pktcdvd.h>
  48 #include <linux/module.h>
  49 #include <linux/types.h>
  50 #include <linux/kernel.h>
  51 #include <linux/kthread.h>
  52 #include <linux/errno.h>
  53 #include <linux/spinlock.h>
  54 #include <linux/file.h>
  55 #include <linux/proc_fs.h>
  56 #include <linux/seq_file.h>
  57 #include <linux/miscdevice.h>
  58 #include <linux/freezer.h>
  59 #include <linux/mutex.h>
  60 #include <scsi/scsi_cmnd.h>
  61 #include <scsi/scsi_ioctl.h>
  62 #include <scsi/scsi.h>
  63 #include <linux/debugfs.h>
  64 #include <linux/device.h>
  65
  66 #include <asm/uaccess.h>
  67
  68 #define DRIVER_NAME     "pktcdvd"
  69
  70 #if PACKET_DEBUG
  71 #define DPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
  72 #else
  73 #define DPRINTK(fmt, args...)
  74 #endif
  75
  76 #if PACKET_DEBUG > 1
  77 #define VPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
  78 #else
  79 #define VPRINTK(fmt, args...)
  80 #endif
  81
  82 #define MAX_SPEED 0xffff
  83
  84 #define ZONE(sector, pd) (((sector) + (pd)->offset) & ~((pd)->settings.size - 1))
  85
  86 static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
  87 static struct proc_dir_entry *pkt_proc;
  88 static int pktdev_major;
  89 static int write_congestion_on  = PKT_WRITE_CONGESTION_ON;
  90 static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
  91 static struct mutex ctl_mutex;  /* Serialize open/close/setup/teardown */
  92 static mempool_t *psd_pool;
  93
  94 static struct class     *class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
  95 static struct dentry    *pkt_debugfs_root = NULL; /* /debug/pktcdvd */
  96
  97 /* forward declaration */
  98 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
  99 static int pkt_remove_dev(dev_t pkt_dev);
 100 static int pkt_seq_show(struct seq_file *m, void *p);
 101
 102
 103
 104 /*
 105  * create and register a pktcdvd kernel object.
 106  */
 107 static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
 108                                         const char* name,
 109                                         struct kobject* parent,
 110                                         struct kobj_type* ktype)
 111 {
 112         struct pktcdvd_kobj *p;
 113         p = kzalloc(sizeof(*p), GFP_KERNEL);
 114         if (!p)
 115                 return NULL;
 116         kobject_set_name(&p->kobj, "%s", name);
 117         p->kobj.parent = parent;
 118         p->kobj.ktype = ktype;
 119         p->pd = pd;
 120         if (kobject_register(&p->kobj) != 0)
 121                 return NULL;
 122         return p;
 123 }
 124 /*
 125  * remove a pktcdvd kernel object.
 126  */
 127 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
 128 {
 129         if (p)
 130                 kobject_unregister(&p->kobj);
 131 }
 132 /*
 133  * default release function for pktcdvd kernel objects.
 134  */
 135 static void pkt_kobj_release(struct kobject *kobj)
 136 {
 137         kfree(to_pktcdvdkobj(kobj));
 138 }
 139
 140
 141 /**********************************************************
 142  *
 143  * sysfs interface for pktcdvd
 144  * by (C) 2006  Thomas Maier <balagi@justmail.de>
 145  *
 146  **********************************************************/
 147
 148 #define DEF_ATTR(_obj,_name,_mode) \
 149         static struct attribute _obj = { \
 150                 .name = _name, .owner = THIS_MODULE, .mode = _mode }
 151
 152 /**********************************************************
 153   /sys/class/pktcdvd/pktcdvd[0-7]/
 154                      stat/reset
 155                      stat/packets_started
 156                      stat/packets_finished
 157                      stat/kb_written
 158                      stat/kb_read
 159                      stat/kb_read_gather
 160                      write_queue/size
 161                      write_queue/congestion_off
 162                      write_queue/congestion_on
 163  **********************************************************/
 164
 165 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
 166 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
 167 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
 168 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
 169 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
 170 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
 171
 172 static struct attribute *kobj_pkt_attrs_stat[] = {
 173         &kobj_pkt_attr_st1,
 174         &kobj_pkt_attr_st2,
 175         &kobj_pkt_attr_st3,
 176         &kobj_pkt_attr_st4,
 177         &kobj_pkt_attr_st5,
 178         &kobj_pkt_attr_st6,
 179         NULL
 180 };
 181
 182 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
 183 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
 184 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
 185
 186 static struct attribute *kobj_pkt_attrs_wqueue[] = {
 187         &kobj_pkt_attr_wq1,
 188         &kobj_pkt_attr_wq2,
 189         &kobj_pkt_attr_wq3,
 190         NULL
 191 };
 192
 193 static ssize_t kobj_pkt_show(struct kobject *kobj,
 194                         struct attribute *attr, char *data)
 195 {
 196         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 197         int n = 0;
 198         int v;
 199         if (strcmp(attr->name, "packets_started") == 0) {
 200                 n = sprintf(data, "%lu\n", pd->stats.pkt_started);
 201
 202         } else if (strcmp(attr->name, "packets_finished") == 0) {
 203                 n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
 204
 205         } else if (strcmp(attr->name, "kb_written") == 0) {
 206                 n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
 207
 208         } else if (strcmp(attr->name, "kb_read") == 0) {
 209                 n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
 210
 211         } else if (strcmp(attr->name, "kb_read_gather") == 0) {
 212                 n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
 213
 214         } else if (strcmp(attr->name, "size") == 0) {
 215                 spin_lock(&pd->lock);
 216                 v = pd->bio_queue_size;
 217                 spin_unlock(&pd->lock);
 218                 n = sprintf(data, "%d\n", v);
 219
 220         } else if (strcmp(attr->name, "congestion_off") == 0) {
 221                 spin_lock(&pd->lock);
 222                 v = pd->write_congestion_off;
 223                 spin_unlock(&pd->lock);
 224                 n = sprintf(data, "%d\n", v);
 225
 226         } else if (strcmp(attr->name, "congestion_on") == 0) {
 227                 spin_lock(&pd->lock);
 228                 v = pd->write_congestion_on;
 229                 spin_unlock(&pd->lock);
 230                 n = sprintf(data, "%d\n", v);
 231         }
 232         return n;
 233 }
 234
 235 static void init_write_congestion_marks(int* lo, int* hi)
 236 {
 237         if (*hi > 0) {
 238                 *hi = max(*hi, 500);
 239                 *hi = min(*hi, 1000000);
 240                 if (*lo <= 0)
 241                         *lo = *hi - 100;
 242                 else {
 243                         *lo = min(*lo, *hi - 100);
 244                         *lo = max(*lo, 100);
 245                 }
 246         } else {
 247                 *hi = -1;
 248                 *lo = -1;
 249         }
 250 }
 251
 252 static ssize_t kobj_pkt_store(struct kobject *kobj,
 253                         struct attribute *attr,
 254                         const char *data, size_t len)
 255 {
 256         struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
 257         int val;
 258
 259         if (strcmp(attr->name, "reset") == 0 && len > 0) {
 260                 pd->stats.pkt_started = 0;
 261                 pd->stats.pkt_ended = 0;
 262                 pd->stats.secs_w = 0;
 263                 pd->stats.secs_rg = 0;
 264                 pd->stats.secs_r = 0;
 265
 266         } else if (strcmp(attr->name, "congestion_off") == 0
 267                    && sscanf(data, "%d", &val) == 1) {
 268                 spin_lock(&pd->lock);
 269                 pd->write_congestion_off = val;
 270                 init_write_congestion_marks(&pd->write_congestion_off,
 271                                         &pd->write_congestion_on);
 272                 spin_unlock(&pd->lock);
 273
 274         } else if (strcmp(attr->name, "congestion_on") == 0
 275                    && sscanf(data, "%d", &val) == 1) {
 276                 spin_lock(&pd->lock);
 277                 pd->write_congestion_on = val;
 278                 init_write_congestion_marks(&pd->write_congestion_off,
 279                                         &pd->write_congestion_on);
 280                 spin_unlock(&pd->lock);
 281         }
 282         return len;
 283 }
 284
 285 static struct sysfs_ops kobj_pkt_ops = {
 286         .show = kobj_pkt_show,
 287         .store = kobj_pkt_store
 288 };
 289 static struct kobj_type kobj_pkt_type_stat = {
 290         .release = pkt_kobj_release,
 291         .sysfs_ops = &kobj_pkt_ops,
 292         .default_attrs = kobj_pkt_attrs_stat
 293 };
 294 static struct kobj_type kobj_pkt_type_wqueue = {
 295         .release = pkt_kobj_release,
 296         .sysfs_ops = &kobj_pkt_ops,
 297         .default_attrs = kobj_pkt_attrs_wqueue
 298 };
 299
 300 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
 301 {
 302         if (class_pktcdvd) {
 303                 pd->clsdev = class_device_create(class_pktcdvd,
 304                                         NULL, pd->pkt_dev,
 305                                         NULL, "%s", pd->name);
 306                 if (IS_ERR(pd->clsdev))
 307                         pd->clsdev = NULL;
 308         }
 309         if (pd->clsdev) {
 310                 pd->kobj_stat = pkt_kobj_create(pd, "stat",
 311                                         &pd->clsdev->kobj,
 312                                         &kobj_pkt_type_stat);
 313                 pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
 314                                         &pd->clsdev->kobj,
 315                                         &kobj_pkt_type_wqueue);
 316         }
 317 }
 318
 319 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
 320 {
 321         pkt_kobj_remove(pd->kobj_stat);
 322         pkt_kobj_remove(pd->kobj_wqueue);
 323         if (class_pktcdvd)
 324                 class_device_destroy(class_pktcdvd, pd->pkt_dev);
 325 }
 326
 327
 328 /********************************************************************
 329   /sys/class/pktcdvd/
 330                      add            map block device
 331                      remove         unmap packet dev
 332                      device_map     show mappings
 333  *******************************************************************/
 334
 335 static void class_pktcdvd_release(struct class *cls)
 336 {
 337         kfree(cls);
 338 }
 339 static ssize_t class_pktcdvd_show_map(struct class *c, char *data)
 340 {
 341         int n = 0;
 342         int idx;
 343         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
 344         for (idx = 0; idx < MAX_WRITERS; idx++) {
 345                 struct pktcdvd_device *pd = pkt_devs[idx];
 346                 if (!pd)
 347                         continue;
 348                 n += sprintf(data+n, "%s %u:%u %u:%u\n",
 349                         pd->name,
 350                         MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 351                         MAJOR(pd->bdev->bd_dev),
 352                         MINOR(pd->bdev->bd_dev));
 353         }
 354         mutex_unlock(&ctl_mutex);
 355         return n;
 356 }
 357
 358 static ssize_t class_pktcdvd_store_add(struct class *c, const char *buf,
 359                                         size_t count)
 360 {
 361         unsigned int major, minor;
 362         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 363                 pkt_setup_dev(MKDEV(major, minor), NULL);
 364                 return count;
 365         }
 366         return -EINVAL;
 367 }
 368
 369 static ssize_t class_pktcdvd_store_remove(struct class *c, const char *buf,
 370                                         size_t count)
 371 {
 372         unsigned int major, minor;
 373         if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
 374                 pkt_remove_dev(MKDEV(major, minor));
 375                 return count;
 376         }
 377         return -EINVAL;
 378 }
 379
 380 static struct class_attribute class_pktcdvd_attrs[] = {
 381  __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
 382  __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
 383  __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
 384  __ATTR_NULL
 385 };
 386
 387
 388 static int pkt_sysfs_init(void)
 389 {
 390         int ret = 0;
 391
 392         /*
 393          * create control files in sysfs
 394          * /sys/class/pktcdvd/...
 395          */
 396         class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
 397         if (!class_pktcdvd)
 398                 return -ENOMEM;
 399         class_pktcdvd->name = DRIVER_NAME;
 400         class_pktcdvd->owner = THIS_MODULE;
 401         class_pktcdvd->class_release = class_pktcdvd_release;
 402         class_pktcdvd->class_attrs = class_pktcdvd_attrs;
 403         ret = class_register(class_pktcdvd);
 404         if (ret) {
 405                 kfree(class_pktcdvd);
 406                 class_pktcdvd = NULL;
 407                 printk(DRIVER_NAME": failed to create class pktcdvd\n");
 408                 return ret;
 409         }
 410         return 0;
 411 }
 412
 413 static void pkt_sysfs_cleanup(void)
 414 {
 415         if (class_pktcdvd)
 416                 class_destroy(class_pktcdvd);
 417         class_pktcdvd = NULL;
 418 }
 419
 420 /********************************************************************
 421   entries in debugfs
 422
 423   /debugfs/pktcdvd[0-7]/
 424                         info
 425
 426  *******************************************************************/
 427
 428 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
 429 {
 430         return pkt_seq_show(m, p);
 431 }
 432
 433 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
 434 {
 435         return single_open(file, pkt_debugfs_seq_show, inode->i_private);
 436 }
 437
 438 static const struct file_operations debug_fops = {
 439         .open           = pkt_debugfs_fops_open,
 440         .read           = seq_read,
 441         .llseek         = seq_lseek,
 442         .release        = single_release,
 443         .owner          = THIS_MODULE,
 444 };
 445
 446 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
 447 {
 448         if (!pkt_debugfs_root)
 449                 return;
 450         pd->dfs_f_info = NULL;
 451         pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
 452         if (IS_ERR(pd->dfs_d_root)) {
 453                 pd->dfs_d_root = NULL;
 454                 return;
 455         }
 456         pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
 457                                 pd->dfs_d_root, pd, &debug_fops);
 458         if (IS_ERR(pd->dfs_f_info)) {
 459                 pd->dfs_f_info = NULL;
 460                 return;
 461         }
 462 }
 463
 464 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
 465 {
 466         if (!pkt_debugfs_root)
 467                 return;
 468         if (pd->dfs_f_info)
 469                 debugfs_remove(pd->dfs_f_info);
 470         pd->dfs_f_info = NULL;
 471         if (pd->dfs_d_root)
 472                 debugfs_remove(pd->dfs_d_root);
 473         pd->dfs_d_root = NULL;
 474 }
 475
 476 static void pkt_debugfs_init(void)
 477 {
 478         pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
 479         if (IS_ERR(pkt_debugfs_root)) {
 480                 pkt_debugfs_root = NULL;
 481                 return;
 482         }
 483 }
 484
 485 static void pkt_debugfs_cleanup(void)
 486 {
 487         if (!pkt_debugfs_root)
 488                 return;
 489         debugfs_remove(pkt_debugfs_root);
 490         pkt_debugfs_root = NULL;
 491 }
 492
 493 /* ----------------------------------------------------------*/
 494
 495
 496 static void pkt_bio_finished(struct pktcdvd_device *pd)
 497 {
 498         BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
 499         if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
 500                 VPRINTK(DRIVER_NAME": queue empty\n");
 501                 atomic_set(&pd->iosched.attention, 1);
 502                 wake_up(&pd->wqueue);
 503         }
 504 }
 505
 506 static void pkt_bio_destructor(struct bio *bio)
 507 {
 508         kfree(bio->bi_io_vec);
 509         kfree(bio);
 510 }
 511
 512 static struct bio *pkt_bio_alloc(int nr_iovecs)
 513 {
 514         struct bio_vec *bvl = NULL;
 515         struct bio *bio;
 516
 517         bio = kmalloc(sizeof(struct bio), GFP_KERNEL);
 518         if (!bio)
 519                 goto no_bio;
 520         bio_init(bio);
 521
 522         bvl = kcalloc(nr_iovecs, sizeof(struct bio_vec), GFP_KERNEL);
 523         if (!bvl)
 524                 goto no_bvl;
 525
 526         bio->bi_max_vecs = nr_iovecs;
 527         bio->bi_io_vec = bvl;
 528         bio->bi_destructor = pkt_bio_destructor;
 529
 530         return bio;
 531
 532  no_bvl:
 533         kfree(bio);
 534  no_bio:
 535         return NULL;
 536 }
 537
 538 /*
 539  * Allocate a packet_data struct
 540  */
 541 static struct packet_data *pkt_alloc_packet_data(int frames)
 542 {
 543         int i;
 544         struct packet_data *pkt;
 545
 546         pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
 547         if (!pkt)
 548                 goto no_pkt;
 549
 550         pkt->frames = frames;
 551         pkt->w_bio = pkt_bio_alloc(frames);
 552         if (!pkt->w_bio)
 553                 goto no_bio;
 554
 555         for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 556                 pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 557                 if (!pkt->pages[i])
 558                         goto no_page;
 559         }
 560
 561         spin_lock_init(&pkt->lock);
 562
 563         for (i = 0; i < frames; i++) {
 564                 struct bio *bio = pkt_bio_alloc(1);
 565                 if (!bio)
 566                         goto no_rd_bio;
 567                 pkt->r_bios[i] = bio;
 568         }
 569
 570         return pkt;
 571
 572 no_rd_bio:
 573         for (i = 0; i < frames; i++) {
 574                 struct bio *bio = pkt->r_bios[i];
 575                 if (bio)
 576                         bio_put(bio);
 577         }
 578
 579 no_page:
 580         for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 581                 if (pkt->pages[i])
 582                         __free_page(pkt->pages[i]);
 583         bio_put(pkt->w_bio);
 584 no_bio:
 585         kfree(pkt);
 586 no_pkt:
 587         return NULL;
 588 }
 589
 590 /*
 591  * Free a packet_data struct
 592  */
 593 static void pkt_free_packet_data(struct packet_data *pkt)
 594 {
 595         int i;
 596
 597         for (i = 0; i < pkt->frames; i++) {
 598                 struct bio *bio = pkt->r_bios[i];
 599                 if (bio)
 600                         bio_put(bio);
 601         }
 602         for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 603                 __free_page(pkt->pages[i]);
 604         bio_put(pkt->w_bio);
 605         kfree(pkt);
 606 }
 607
 608 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
 609 {
 610         struct packet_data *pkt, *next;
 611
 612         BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
 613
 614         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 615                 pkt_free_packet_data(pkt);
 616         }
 617         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 618 }
 619
 620 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 621 {
 622         struct packet_data *pkt;
 623
 624         BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
 625
 626         while (nr_packets > 0) {
 627                 pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 628                 if (!pkt) {
 629                         pkt_shrink_pktlist(pd);
 630                         return 0;
 631                 }
 632                 pkt->id = nr_packets;
 633                 pkt->pd = pd;
 634                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
 635                 nr_packets--;
 636         }
 637         return 1;
 638 }
 639
 640 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
 641 {
 642         struct rb_node *n = rb_next(&node->rb_node);
 643         if (!n)
 644                 return NULL;
 645         return rb_entry(n, struct pkt_rb_node, rb_node);
 646 }
 647
 648 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 649 {
 650         rb_erase(&node->rb_node, &pd->bio_queue);
 651         mempool_free(node, pd->rb_pool);
 652         pd->bio_queue_size--;
 653         BUG_ON(pd->bio_queue_size < 0);
 654 }
 655
 656 /*
 657  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
 658  */
 659 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
 660 {
 661         struct rb_node *n = pd->bio_queue.rb_node;
 662         struct rb_node *next;
 663         struct pkt_rb_node *tmp;
 664
 665         if (!n) {
 666                 BUG_ON(pd->bio_queue_size > 0);
 667                 return NULL;
 668         }
 669
 670         for (;;) {
 671                 tmp = rb_entry(n, struct pkt_rb_node, rb_node);
 672                 if (s <= tmp->bio->bi_sector)
 673                         next = n->rb_left;
 674                 else
 675                         next = n->rb_right;
 676                 if (!next)
 677                         break;
 678                 n = next;
 679         }
 680
 681         if (s > tmp->bio->bi_sector) {
 682                 tmp = pkt_rbtree_next(tmp);
 683                 if (!tmp)
 684                         return NULL;
 685         }
 686         BUG_ON(s > tmp->bio->bi_sector);
 687         return tmp;
 688 }
 689
 690 /*
 691  * Insert a node into the pd->bio_queue rb tree.
 692  */
 693 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
 694 {
 695         struct rb_node **p = &pd->bio_queue.rb_node;
 696         struct rb_node *parent = NULL;
 697         sector_t s = node->bio->bi_sector;
 698         struct pkt_rb_node *tmp;
 699
 700         while (*p) {
 701                 parent = *p;
 702                 tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
 703                 if (s < tmp->bio->bi_sector)
 704                         p = &(*p)->rb_left;
 705                 else
 706                         p = &(*p)->rb_right;
 707         }
 708         rb_link_node(&node->rb_node, parent, p);
 709         rb_insert_color(&node->rb_node, &pd->bio_queue);
 710         pd->bio_queue_size++;
 711 }
 712
 713 /*
 714  * Add a bio to a single linked list defined by its head and tail pointers.
 715  */
 716 static void pkt_add_list_last(struct bio *bio, struct bio **list_head, struct bio **list_tail)
 717 {
 718         bio->bi_next = NULL;
 719         if (*list_tail) {
 720                 BUG_ON((*list_head) == NULL);
 721                 (*list_tail)->bi_next = bio;
 722                 (*list_tail) = bio;
 723         } else {
 724                 BUG_ON((*list_head) != NULL);
 725                 (*list_head) = bio;
 726                 (*list_tail) = bio;
 727         }
 728 }
 729
 730 /*
 731  * Remove and return the first bio from a single linked list defined by its
 732  * head and tail pointers.
 733  */
 734 static inline struct bio *pkt_get_list_first(struct bio **list_head, struct bio **list_tail)
 735 {
 736         struct bio *bio;
 737
 738         if (*list_head == NULL)
 739                 return NULL;
 740
 741         bio = *list_head;
 742         *list_head = bio->bi_next;
 743         if (*list_head == NULL)
 744                 *list_tail = NULL;
 745
 746         bio->bi_next = NULL;
 747         return bio;
 748 }
 749
 750 /*
 751  * Send a packet_command to the underlying block device and
 752  * wait for completion.
 753  */
 754 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
 755 {
 756         request_queue_t *q = bdev_get_queue(pd->bdev);
 757         struct request *rq;
 758         int ret = 0;
 759
 760         rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 761                              WRITE : READ, __GFP_WAIT);
 762
 763         if (cgc->buflen) {
 764                 if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
 765                         goto out;
 766         }
 767
 768         rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 769         memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 770         if (sizeof(rq->cmd) > CDROM_PACKET_SIZE)
 771                 memset(rq->cmd + CDROM_PACKET_SIZE, 0, sizeof(rq->cmd) - CDROM_PACKET_SIZE);
 772
 773         rq->timeout = 60*HZ;
 774         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 775         rq->cmd_flags |= REQ_HARDBARRIER;
 776         if (cgc->quiet)
 777                 rq->cmd_flags |= REQ_QUIET;
 778
 779         blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
 780         if (rq->errors)
 781                 ret = -EIO;
 782 out:
 783         blk_put_request(rq);
 784         return ret;
 785 }
 786
 787 /*
 788  * A generic sense dump / resolve mechanism should be implemented across
 789  * all ATAPI + SCSI devices.
 790  */
 791 static void pkt_dump_sense(struct packet_command *cgc)
 792 {
 793         static char *info[9] = { "No sense", "Recovered error", "Not ready",
 794                                  "Medium error", "Hardware error", "Illegal request",
 795                                  "Unit attention", "Data protect", "Blank check" };
 796         int i;
 797         struct request_sense *sense = cgc->sense;
 798
 799         printk(DRIVER_NAME":");
 800         for (i = 0; i < CDROM_PACKET_SIZE; i++)
 801                 printk(" %02x", cgc->cmd[i]);
 802         printk(" - ");
 803
 804         if (sense == NULL) {
 805                 printk("no sense\n");
 806                 return;
 807         }
 808
 809         printk("sense %02x.%02x.%02x", sense->sense_key, sense->asc, sense->ascq);
 810
 811         if (sense->sense_key > 8) {
 812                 printk(" (INVALID)\n");
 813                 return;
 814         }
 815
 816         printk(" (%s)\n", info[sense->sense_key]);
 817 }
 818
 819 /*
 820  * flush the drive cache to media
 821  */
 822 static int pkt_flush_cache(struct pktcdvd_device *pd)
 823 {
 824         struct packet_command cgc;
 825
 826         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 827         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 828         cgc.quiet = 1;
 829
 830         /*
 831          * the IMMED bit -- we default to not setting it, although that
 832          * would allow a much faster close, this is safer
 833          */
 834 #if 0
 835         cgc.cmd[1] = 1 << 1;
 836 #endif
 837         return pkt_generic_packet(pd, &cgc);
 838 }
 839
 840 /*
 841  * speed is given as the normal factor, e.g. 4 for 4x
 842  */
 843 static int pkt_set_speed(struct pktcdvd_device *pd, unsigned write_speed, unsigned read_speed)
 844 {
 845         struct packet_command cgc;
 846         struct request_sense sense;
 847         int ret;
 848
 849         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 850         cgc.sense = &sense;
 851         cgc.cmd[0] = GPCMD_SET_SPEED;
 852         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 853         cgc.cmd[3] = read_speed & 0xff;
 854         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 855         cgc.cmd[5] = write_speed & 0xff;
 856
 857         if ((ret = pkt_generic_packet(pd, &cgc)))
 858                 pkt_dump_sense(&cgc);
 859
 860         return ret;
 861 }
 862
 863 /*
 864  * Queue a bio for processing by the low-level CD device. Must be called
 865  * from process context.
 866  */
 867 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 868 {
 869         spin_lock(&pd->iosched.lock);
 870         if (bio_data_dir(bio) == READ) {
 871                 pkt_add_list_last(bio, &pd->iosched.read_queue,
 872                                   &pd->iosched.read_queue_tail);
 873         } else {
 874                 pkt_add_list_last(bio, &pd->iosched.write_queue,
 875                                   &pd->iosched.write_queue_tail);
 876         }
 877         spin_unlock(&pd->iosched.lock);
 878
 879         atomic_set(&pd->iosched.attention, 1);
 880         wake_up(&pd->wqueue);
 881 }
 882
 883 /*
 884  * Process the queued read/write requests. This function handles special
 885  * requirements for CDRW drives:
 886  * - A cache flush command must be inserted before a read request if the
 887  *   previous request was a write.
 888  * - Switching between reading and writing is slow, so don't do it more often
 889  *   than necessary.
 890  * - Optimize for throughput at the expense of latency. This means that streaming
 891  *   writes will never be interrupted by a read, but if the drive has to seek
 892  *   before the next write, switch to reading instead if there are any pending
 893  *   read requests.
 894  * - Set the read speed according to current usage pattern. When only reading
 895  *   from the device, it's best to use the highest possible read speed, but
 896  *   when switching often between reading and writing, it's better to have the
 897  *   same read and write speeds.
 898  */
 899 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 900 {
 901
 902         if (atomic_read(&pd->iosched.attention) == 0)
 903                 return;
 904         atomic_set(&pd->iosched.attention, 0);
 905
 906         for (;;) {
 907                 struct bio *bio;
 908                 int reads_queued, writes_queued;
 909
 910                 spin_lock(&pd->iosched.lock);
 911                 reads_queued = (pd->iosched.read_queue != NULL);
 912                 writes_queued = (pd->iosched.write_queue != NULL);
 913                 spin_unlock(&pd->iosched.lock);
 914
 915                 if (!reads_queued && !writes_queued)
 916                         break;
 917
 918                 if (pd->iosched.writing) {
 919                         int need_write_seek = 1;
 920                         spin_lock(&pd->iosched.lock);
 921                         bio = pd->iosched.write_queue;
 922                         spin_unlock(&pd->iosched.lock);
 923                         if (bio && (bio->bi_sector == pd->iosched.last_write))
 924                                 need_write_seek = 0;
 925                         if (need_write_seek && reads_queued) {
 926                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 927                                         VPRINTK(DRIVER_NAME": write, waiting\n");
 928                                         break;
 929                                 }
 930                                 pkt_flush_cache(pd);
 931                                 pd->iosched.writing = 0;
 932                         }
 933                 } else {
 934                         if (!reads_queued && writes_queued) {
 935                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 936                                         VPRINTK(DRIVER_NAME": read, waiting\n");
 937                                         break;
 938                                 }
 939                                 pd->iosched.writing = 1;
 940                         }
 941                 }
 942
 943                 spin_lock(&pd->iosched.lock);
 944                 if (pd->iosched.writing) {
 945                         bio = pkt_get_list_first(&pd->iosched.write_queue,
 946                                                  &pd->iosched.write_queue_tail);
 947                 } else {
 948                         bio = pkt_get_list_first(&pd->iosched.read_queue,
 949                                                  &pd->iosched.read_queue_tail);
 950                 }
 951                 spin_unlock(&pd->iosched.lock);
 952
 953                 if (!bio)
 954                         continue;
 955
 956                 if (bio_data_dir(bio) == READ)
 957                         pd->iosched.successive_reads += bio->bi_size >> 10;
 958                 else {
 959                         pd->iosched.successive_reads = 0;
 960                         pd->iosched.last_write = bio->bi_sector + bio_sectors(bio);
 961                 }
 962                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 963                         if (pd->read_speed == pd->write_speed) {
 964                                 pd->read_speed = MAX_SPEED;
 965                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 966                         }
 967                 } else {
 968                         if (pd->read_speed != pd->write_speed) {
 969                                 pd->read_speed = pd->write_speed;
 970                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 971                         }
 972                 }
 973
 974                 atomic_inc(&pd->cdrw.pending_bios);
 975                 generic_make_request(bio);
 976         }
 977 }
 978
 979 /*
 980  * Special care is needed if the underlying block device has a small
 981  * max_phys_segments value.
 982  */
 983 static int pkt_set_segment_merging(struct pktcdvd_device *pd, request_queue_t *q)
 984 {
 985         if ((pd->settings.size << 9) / CD_FRAMESIZE <= q->max_phys_segments) {
 986                 /*
 987                  * The cdrom device can handle one segment/frame
 988                  */
 989                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 990                 return 0;
 991         } else if ((pd->settings.size << 9) / PAGE_SIZE <= q->max_phys_segments) {
 992                 /*
 993                  * We can handle this case at the expense of some extra memory
 994                  * copies during write operations
 995                  */
 996                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 997                 return 0;
 998         } else {
 999                 printk(DRIVER_NAME": cdrom max_phys_segments too small\n");
1000                 return -EIO;
1001         }
1002 }
1003
1004 /*
1005  * Copy CD_FRAMESIZE bytes from src_bio into a destination page
1006  */
1007 static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
1008 {
1009         unsigned int copy_size = CD_FRAMESIZE;
1010
1011         while (copy_size > 0) {
1012                 struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
1013                 void *vfrom = kmap_atomic(src_bvl->bv_page, KM_USER0) +
1014                         src_bvl->bv_offset + offs;
1015                 void *vto = page_address(dst_page) + dst_offs;
1016                 int len = min_t(int, copy_size, src_bvl->bv_len - offs);
1017
1018                 BUG_ON(len < 0);
1019                 memcpy(vto, vfrom, len);
1020                 kunmap_atomic(vfrom, KM_USER0);
1021
1022                 seg++;
1023                 offs = 0;
1024                 dst_offs += len;
1025                 copy_size -= len;
1026         }
1027 }
1028
1029 /*
1030  * Copy all data for this packet to pkt->pages[], so that
1031  * a) The number of required segments for the write bio is minimized, which
1032  *    is necessary for some scsi controllers.
1033  * b) The data can be used as cache to avoid read requests if we receive a
1034  *    new write request for the same zone.
1035  */
1036 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
1037 {
1038         int f, p, offs;
1039
1040         /* Copy all data to pkt->pages[] */
1041         p = 0;
1042         offs = 0;
1043         for (f = 0; f < pkt->frames; f++) {
1044                 if (bvec[f].bv_page != pkt->pages[p]) {
1045                         void *vfrom = kmap_atomic(bvec[f].bv_page, KM_USER0) + bvec[f].bv_offset;
1046                         void *vto = page_address(pkt->pages[p]) + offs;
1047                         memcpy(vto, vfrom, CD_FRAMESIZE);
1048                         kunmap_atomic(vfrom, KM_USER0);
1049                         bvec[f].bv_page = pkt->pages[p];
1050                         bvec[f].bv_offset = offs;
1051                 } else {
1052                         BUG_ON(bvec[f].bv_offset != offs);
1053                 }
1054                 offs += CD_FRAMESIZE;
1055                 if (offs >= PAGE_SIZE) {
1056                         offs = 0;
1057                         p++;
1058                 }
1059         }
1060 }
1061
1062 static int pkt_end_io_read(struct bio *bio, unsigned int bytes_done, int err)
1063 {
1064         struct packet_data *pkt = bio->bi_private;
1065         struct pktcdvd_device *pd = pkt->pd;
1066         BUG_ON(!pd);
1067
1068         if (bio->bi_size)
1069                 return 1;
1070
1071         VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
1072                 (unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
1073
1074         if (err)
1075                 atomic_inc(&pkt->io_errors);
1076         if (atomic_dec_and_test(&pkt->io_wait)) {
1077                 atomic_inc(&pkt->run_sm);
1078                 wake_up(&pd->wqueue);
1079         }
1080         pkt_bio_finished(pd);
1081
1082         return 0;
1083 }
1084
1085 static int pkt_end_io_packet_write(struct bio *bio, unsigned int bytes_done, int err)
1086 {
1087         struct packet_data *pkt = bio->bi_private;
1088         struct pktcdvd_device *pd = pkt->pd;
1089         BUG_ON(!pd);
1090
1091         if (bio->bi_size)
1092                 return 1;
1093
1094         VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
1095
1096         pd->stats.pkt_ended++;
1097
1098         pkt_bio_finished(pd);
1099         atomic_dec(&pkt->io_wait);
1100         atomic_inc(&pkt->run_sm);
1101         wake_up(&pd->wqueue);
1102         return 0;
1103 }
1104
1105 /*
1106  * Schedule reads for the holes in a packet
1107  */
1108 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1109 {
1110         int frames_read = 0;
1111         struct bio *bio;
1112         int f;
1113         char written[PACKET_MAX_SIZE];
1114
1115         BUG_ON(!pkt->orig_bios);
1116
1117         atomic_set(&pkt->io_wait, 0);
1118         atomic_set(&pkt->io_errors, 0);
1119
1120         /*
1121          * Figure out which frames we need to read before we can write.
1122          */
1123         memset(written, 0, sizeof(written));
1124         spin_lock(&pkt->lock);
1125         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1126                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1127                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1128                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1129                 BUG_ON(first_frame < 0);
1130                 BUG_ON(first_frame + num_frames > pkt->frames);
1131                 for (f = first_frame; f < first_frame + num_frames; f++)
1132                         written[f] = 1;
1133         }
1134         spin_unlock(&pkt->lock);
1135
1136         if (pkt->cache_valid) {
1137                 VPRINTK("pkt_gather_data: zone %llx cached\n",
1138                         (unsigned long long)pkt->sector);
1139                 goto out_account;
1140         }
1141
1142         /*
1143          * Schedule reads for missing parts of the packet.
1144          */
1145         for (f = 0; f < pkt->frames; f++) {
1146                 int p, offset;
1147                 if (written[f])
1148                         continue;
1149                 bio = pkt->r_bios[f];
1150                 bio_init(bio);
1151                 bio->bi_max_vecs = 1;
1152                 bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1153                 bio->bi_bdev = pd->bdev;
1154                 bio->bi_end_io = pkt_end_io_read;
1155                 bio->bi_private = pkt;
1156
1157                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1158                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1159                 VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
1160                         f, pkt->pages[p], offset);
1161                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1162                         BUG();
1163
1164                 atomic_inc(&pkt->io_wait);
1165                 bio->bi_rw = READ;
1166                 pkt_queue_bio(pd, bio);
1167                 frames_read++;
1168         }
1169
1170 out_account:
1171         VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
1172                 frames_read, (unsigned long long)pkt->sector);
1173         pd->stats.pkt_started++;
1174         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1175 }
1176
1177 /*
1178  * Find a packet matching zone, or the least recently used packet if
1179  * there is no match.
1180  */
1181 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1182 {
1183         struct packet_data *pkt;
1184
1185         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1186                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1187                         list_del_init(&pkt->list);
1188                         if (pkt->sector != zone)
1189                                 pkt->cache_valid = 0;
1190                         return pkt;
1191                 }
1192         }
1193         BUG();
1194         return NULL;
1195 }
1196
1197 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1198 {
1199         if (pkt->cache_valid) {
1200                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1201         } else {
1202                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1203         }
1204 }
1205
1206 /*
1207  * recover a failed write, query for relocation if possible
1208  *
1209  * returns 1 if recovery is possible, or 0 if not
1210  *
1211  */
1212 static int pkt_start_recovery(struct packet_data *pkt)
1213 {
1214         /*
1215          * FIXME. We need help from the file system to implement
1216          * recovery handling.
1217          */
1218         return 0;
1219 #if 0
1220         struct request *rq = pkt->rq;
1221         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1222         struct block_device *pkt_bdev;
1223         struct super_block *sb = NULL;
1224         unsigned long old_block, new_block;
1225         sector_t new_sector;
1226
1227         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1228         if (pkt_bdev) {
1229                 sb = get_super(pkt_bdev);
1230                 bdput(pkt_bdev);
1231         }
1232
1233         if (!sb)
1234                 return 0;
1235
1236         if (!sb->s_op || !sb->s_op->relocate_blocks)
1237                 goto out;
1238
1239         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1240         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1241                 goto out;
1242
1243         new_sector = new_block * (CD_FRAMESIZE >> 9);
1244         pkt->sector = new_sector;
1245
1246         pkt->bio->bi_sector = new_sector;
1247         pkt->bio->bi_next = NULL;
1248         pkt->bio->bi_flags = 1 << BIO_UPTODATE;
1249         pkt->bio->bi_idx = 0;
1250
1251         BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
1252         BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
1253         BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
1254         BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
1255         BUG_ON(pkt->bio->bi_private != pkt);
1256
1257         drop_super(sb);
1258         return 1;
1259
1260 out:
1261         drop_super(sb);
1262         return 0;
1263 #endif
1264 }
1265
1266 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1267 {
1268 #if PACKET_DEBUG > 1
1269         static const char *state_name[] = {
1270                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1271         };
1272         enum packet_data_state old_state = pkt->state;
1273         VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
1274                 state_name[old_state], state_name[state]);
1275 #endif
1276         pkt->state = state;
1277 }
1278
1279 /*
1280  * Scan the work queue to see if we can start a new packet.
1281  * returns non-zero if any work was done.
1282  */
1283 static int pkt_handle_queue(struct pktcdvd_device *pd)
1284 {
1285         struct packet_data *pkt, *p;
1286         struct bio *bio = NULL;
1287         sector_t zone = 0; /* Suppress gcc warning */
1288         struct pkt_rb_node *node, *first_node;
1289         struct rb_node *n;
1290         int wakeup;
1291
1292         VPRINTK("handle_queue\n");
1293
1294         atomic_set(&pd->scan_queue, 0);
1295
1296         if (list_empty(&pd->cdrw.pkt_free_list)) {
1297                 VPRINTK("handle_queue: no pkt\n");
1298                 return 0;
1299         }
1300
1301         /*
1302          * Try to find a zone we are not already working on.
1303          */
1304         spin_lock(&pd->lock);
1305         first_node = pkt_rbtree_find(pd, pd->current_sector);
1306         if (!first_node) {
1307                 n = rb_first(&pd->bio_queue);
1308                 if (n)
1309                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1310         }
1311         node = first_node;
1312         while (node) {
1313                 bio = node->bio;
1314                 zone = ZONE(bio->bi_sector, pd);
1315                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1316                         if (p->sector == zone) {
1317                                 bio = NULL;
1318                                 goto try_next_bio;
1319                         }
1320                 }
1321                 break;
1322 try_next_bio:
1323                 node = pkt_rbtree_next(node);
1324                 if (!node) {
1325                         n = rb_first(&pd->bio_queue);
1326                         if (n)
1327                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1328                 }
1329                 if (node == first_node)
1330                         node = NULL;
1331         }
1332         spin_unlock(&pd->lock);
1333         if (!bio) {
1334                 VPRINTK("handle_queue: no bio\n");
1335                 return 0;
1336         }
1337
1338         pkt = pkt_get_packet_data(pd, zone);
1339
1340         pd->current_sector = zone + pd->settings.size;
1341         pkt->sector = zone;
1342         BUG_ON(pkt->frames != pd->settings.size >> 2);
1343         pkt->write_size = 0;
1344
1345         /*
1346          * Scan work queue for bios in the same zone and link them
1347          * to this packet.
1348          */
1349         spin_lock(&pd->lock);
1350         VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
1351         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1352                 bio = node->bio;
1353                 VPRINTK("pkt_handle_queue: found zone=%llx\n",
1354                         (unsigned long long)ZONE(bio->bi_sector, pd));
1355                 if (ZONE(bio->bi_sector, pd) != zone)
1356                         break;
1357                 pkt_rbtree_erase(pd, node);
1358                 spin_lock(&pkt->lock);
1359                 pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
1360                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
1361                 spin_unlock(&pkt->lock);
1362         }
1363         /* check write congestion marks, and if bio_queue_size is
1364            below, wake up any waiters */
1365         wakeup = (pd->write_congestion_on > 0
1366                         && pd->bio_queue_size <= pd->write_congestion_off);
1367         spin_unlock(&pd->lock);
1368         if (wakeup)
1369                 clear_bdi_congested(&pd->disk->queue->backing_dev_info, WRITE);
1370
1371         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1372         pkt_set_state(pkt, PACKET_WAITING_STATE);
1373         atomic_set(&pkt->run_sm, 1);
1374
1375         spin_lock(&pd->cdrw.active_list_lock);
1376         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1377         spin_unlock(&pd->cdrw.active_list_lock);
1378
1379         return 1;
1380 }
1381
1382 /*
1383  * Assemble a bio to write one packet and queue the bio for processing
1384  * by the underlying block device.
1385  */
1386 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1387 {
1388         struct bio *bio;
1389         int f;
1390         int frames_write;
1391         struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1392
1393         for (f = 0; f < pkt->frames; f++) {
1394                 bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1395                 bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1396         }
1397
1398         /*
1399          * Fill-in bvec with data from orig_bios.
1400          */
1401         frames_write = 0;
1402         spin_lock(&pkt->lock);
1403         for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1404                 int segment = bio->bi_idx;
1405                 int src_offs = 0;
1406                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1407                 int num_frames = bio->bi_size / CD_FRAMESIZE;
1408                 BUG_ON(first_frame < 0);
1409                 BUG_ON(first_frame + num_frames > pkt->frames);
1410                 for (f = first_frame; f < first_frame + num_frames; f++) {
1411                         struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
1412
1413                         while (src_offs >= src_bvl->bv_len) {
1414                                 src_offs -= src_bvl->bv_len;
1415                                 segment++;
1416                                 BUG_ON(segment >= bio->bi_vcnt);
1417                                 src_bvl = bio_iovec_idx(bio, segment);
1418                         }
1419
1420                         if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
1421                                 bvec[f].bv_page = src_bvl->bv_page;
1422                                 bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
1423                         } else {
1424                                 pkt_copy_bio_data(bio, segment, src_offs,
1425                                                   bvec[f].bv_page, bvec[f].bv_offset);
1426                         }
1427                         src_offs += CD_FRAMESIZE;
1428                         frames_write++;
1429                 }
1430         }
1431         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1432         spin_unlock(&pkt->lock);
1433
1434         VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
1435                 frames_write, (unsigned long long)pkt->sector);
1436         BUG_ON(frames_write != pkt->write_size);
1437
1438         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1439                 pkt_make_local_copy(pkt, bvec);
1440                 pkt->cache_valid = 1;
1441         } else {
1442                 pkt->cache_valid = 0;
1443         }
1444
1445         /* Start the write request */
1446         bio_init(pkt->w_bio);
1447         pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
1448         pkt->w_bio->bi_sector = pkt->sector;
1449         pkt->w_bio->bi_bdev = pd->bdev;
1450         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1451         pkt->w_bio->bi_private = pkt;
1452         for (f = 0; f < pkt->frames; f++)
1453                 if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1454                         BUG();
1455         VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
1456
1457         atomic_set(&pkt->io_wait, 1);
1458         pkt->w_bio->bi_rw = WRITE;
1459         pkt_queue_bio(pd, pkt->w_bio);
1460 }
1461
1462 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1463 {
1464         struct bio *bio, *next;
1465
1466         if (!uptodate)
1467                 pkt->cache_valid = 0;
1468
1469         /* Finish all bios corresponding to this packet */
1470         bio = pkt->orig_bios;
1471         while (bio) {
1472                 next = bio->bi_next;
1473                 bio->bi_next = NULL;
1474                 bio_endio(bio, bio->bi_size, uptodate ? 0 : -EIO);
1475                 bio = next;
1476         }
1477         pkt->orig_bios = pkt->orig_bios_tail = NULL;
1478 }
1479
1480 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1481 {
1482         int uptodate;
1483
1484         VPRINTK("run_state_machine: pkt %d\n", pkt->id);
1485
1486         for (;;) {
1487                 switch (pkt->state) {
1488                 case PACKET_WAITING_STATE:
1489                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1490                                 return;
1491
1492                         pkt->sleep_time = 0;
1493                         pkt_gather_data(pd, pkt);
1494                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1495                         break;
1496
1497                 case PACKET_READ_WAIT_STATE:
1498                         if (atomic_read(&pkt->io_wait) > 0)
1499                                 return;
1500
1501                         if (atomic_read(&pkt->io_errors) > 0) {
1502                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1503                         } else {
1504                                 pkt_start_write(pd, pkt);
1505                         }
1506                         break;
1507
1508                 case PACKET_WRITE_WAIT_STATE:
1509                         if (atomic_read(&pkt->io_wait) > 0)
1510                                 return;
1511
1512                         if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1513                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1514                         } else {
1515                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1516                         }
1517                         break;
1518
1519                 case PACKET_RECOVERY_STATE:
1520                         if (pkt_start_recovery(pkt)) {
1521                                 pkt_start_write(pd, pkt);
1522                         } else {
1523                                 VPRINTK("No recovery possible\n");
1524                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1525                         }
1526                         break;
1527
1528                 case PACKET_FINISHED_STATE:
1529                         uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1530                         pkt_finish_packet(pkt, uptodate);
1531                         return;
1532
1533                 default:
1534                         BUG();
1535                         break;
1536                 }
1537         }
1538 }
1539
1540 static void pkt_handle_packets(struct pktcdvd_device *pd)
1541 {
1542         struct packet_data *pkt, *next;
1543
1544         VPRINTK("pkt_handle_packets\n");
1545
1546         /*
1547          * Run state machine for active packets
1548          */
1549         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1550                 if (atomic_read(&pkt->run_sm) > 0) {
1551                         atomic_set(&pkt->run_sm, 0);
1552                         pkt_run_state_machine(pd, pkt);
1553                 }
1554         }
1555
1556         /*
1557          * Move no longer active packets to the free list
1558          */
1559         spin_lock(&pd->cdrw.active_list_lock);
1560         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1561                 if (pkt->state == PACKET_FINISHED_STATE) {
1562                         list_del(&pkt->list);
1563                         pkt_put_packet_data(pd, pkt);
1564                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1565                         atomic_set(&pd->scan_queue, 1);
1566                 }
1567         }
1568         spin_unlock(&pd->cdrw.active_list_lock);
1569 }
1570
1571 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1572 {
1573         struct packet_data *pkt;
1574         int i;
1575
1576         for (i = 0; i < PACKET_NUM_STATES; i++)
1577                 states[i] = 0;
1578
1579         spin_lock(&pd->cdrw.active_list_lock);
1580         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1581                 states[pkt->state]++;
1582         }
1583         spin_unlock(&pd->cdrw.active_list_lock);
1584 }
1585
1586 /*
1587  * kcdrwd is woken up when writes have been queued for one of our
1588  * registered devices
1589  */
1590 static int kcdrwd(void *foobar)
1591 {
1592         struct pktcdvd_device *pd = foobar;
1593         struct packet_data *pkt;
1594         long min_sleep_time, residue;
1595
1596         set_user_nice(current, -20);
1597
1598         for (;;) {
1599                 DECLARE_WAITQUEUE(wait, current);
1600
1601                 /*
1602                  * Wait until there is something to do
1603                  */
1604                 add_wait_queue(&pd->wqueue, &wait);
1605                 for (;;) {
1606                         set_current_state(TASK_INTERRUPTIBLE);
1607
1608                         /* Check if we need to run pkt_handle_queue */
1609                         if (atomic_read(&pd->scan_queue) > 0)
1610                                 goto work_to_do;
1611
1612                         /* Check if we need to run the state machine for some packet */
1613                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1614                                 if (atomic_read(&pkt->run_sm) > 0)
1615                                         goto work_to_do;
1616                         }
1617
1618                         /* Check if we need to process the iosched queues */
1619                         if (atomic_read(&pd->iosched.attention) != 0)
1620                                 goto work_to_do;
1621
1622                         /* Otherwise, go to sleep */
1623                         if (PACKET_DEBUG > 1) {
1624                                 int states[PACKET_NUM_STATES];
1625                                 pkt_count_states(pd, states);
1626                                 VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1627                                         states[0], states[1], states[2], states[3],
1628                                         states[4], states[5]);
1629                         }
1630
1631                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1632                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1633                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1634                                         min_sleep_time = pkt->sleep_time;
1635                         }
1636
1637                         generic_unplug_device(bdev_get_queue(pd->bdev));
1638
1639                         VPRINTK("kcdrwd: sleeping\n");
1640                         residue = schedule_timeout(min_sleep_time);
1641                         VPRINTK("kcdrwd: wake up\n");
1642
1643                         /* make swsusp happy with our thread */
1644                         try_to_freeze();
1645
1646                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1647                                 if (!pkt->sleep_time)
1648                                         continue;
1649                                 pkt->sleep_time -= min_sleep_time - residue;
1650                                 if (pkt->sleep_time <= 0) {
1651                                         pkt->sleep_time = 0;
1652                                         atomic_inc(&pkt->run_sm);
1653                                 }
1654                         }
1655
1656                         if (signal_pending(current)) {
1657                                 flush_signals(current);
1658                         }
1659                         if (kthread_should_stop())
1660                                 break;
1661                 }
1662 work_to_do:
1663                 set_current_state(TASK_RUNNING);
1664                 remove_wait_queue(&pd->wqueue, &wait);
1665
1666                 if (kthread_should_stop())
1667                         break;
1668
1669                 /*
1670                  * if pkt_handle_queue returns true, we can queue
1671                  * another request.
1672                  */
1673                 while (pkt_handle_queue(pd))
1674                         ;
1675
1676                 /*
1677                  * Handle packet state machine
1678                  */
1679                 pkt_handle_packets(pd);
1680
1681                 /*
1682                  * Handle iosched queues
1683                  */
1684                 pkt_iosched_process_queue(pd);
1685         }
1686
1687         return 0;
1688 }
1689
1690 static void pkt_print_settings(struct pktcdvd_device *pd)
1691 {
1692         printk(DRIVER_NAME": %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
1693         printk("%u blocks, ", pd->settings.size >> 2);
1694         printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
1695 }
1696
1697 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1698 {
1699         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1700
1701         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1702         cgc->cmd[2] = page_code | (page_control << 6);
1703         cgc->cmd[7] = cgc->buflen >> 8;
1704         cgc->cmd[8] = cgc->buflen & 0xff;
1705         cgc->data_direction = CGC_DATA_READ;
1706         return pkt_generic_packet(pd, cgc);
1707 }
1708
1709 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1710 {
1711         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1712         memset(cgc->buffer, 0, 2);
1713         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1714         cgc->cmd[1] = 0x10;             /* PF */
1715         cgc->cmd[7] = cgc->buflen >> 8;
1716         cgc->cmd[8] = cgc->buflen & 0xff;
1717         cgc->data_direction = CGC_DATA_WRITE;
1718         return pkt_generic_packet(pd, cgc);
1719 }
1720
1721 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1722 {
1723         struct packet_command cgc;
1724         int ret;
1725
1726         /* set up command and get the disc info */
1727         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1728         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1729         cgc.cmd[8] = cgc.buflen = 2;
1730         cgc.quiet = 1;
1731
1732         if ((ret = pkt_generic_packet(pd, &cgc)))
1733                 return ret;
1734
1735         /* not all drives have the same disc_info length, so requeue
1736          * packet with the length the drive tells us it can supply
1737          */
1738         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1739                      sizeof(di->disc_information_length);
1740
1741         if (cgc.buflen > sizeof(disc_information))
1742                 cgc.buflen = sizeof(disc_information);
1743
1744         cgc.cmd[8] = cgc.buflen;
1745         return pkt_generic_packet(pd, &cgc);
1746 }
1747
1748 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1749 {
1750         struct packet_command cgc;
1751         int ret;
1752
1753         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1754         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1755         cgc.cmd[1] = type & 3;
1756         cgc.cmd[4] = (track & 0xff00) >> 8;
1757         cgc.cmd[5] = track & 0xff;
1758         cgc.cmd[8] = 8;
1759         cgc.quiet = 1;
1760
1761         if ((ret = pkt_generic_packet(pd, &cgc)))
1762                 return ret;
1763
1764         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1765                      sizeof(ti->track_information_length);
1766
1767         if (cgc.buflen > sizeof(track_information))
1768                 cgc.buflen = sizeof(track_information);
1769
1770         cgc.cmd[8] = cgc.buflen;
1771         return pkt_generic_packet(pd, &cgc);
1772 }
1773
1774 static int pkt_get_last_written(struct pktcdvd_device *pd, long *last_written)
1775 {
1776         disc_information di;
1777         track_information ti;
1778         __u32 last_track;
1779         int ret = -1;
1780
1781         if ((ret = pkt_get_disc_info(pd, &di)))
1782                 return ret;
1783
1784         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1785         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1786                 return ret;
1787
1788         /* if this track is blank, try the previous. */
1789         if (ti.blank) {
1790                 last_track--;
1791                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1792                         return ret;
1793         }
1794
1795         /* if last recorded field is valid, return it. */
1796         if (ti.lra_v) {
1797                 *last_written = be32_to_cpu(ti.last_rec_address);
1798         } else {
1799                 /* make it up instead */
1800                 *last_written = be32_to_cpu(ti.track_start) +
1801                                 be32_to_cpu(ti.track_size);
1802                 if (ti.free_blocks)
1803                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1804         }
1805         return 0;
1806 }
1807
1808 /*
1809  * write mode select package based on pd->settings
1810  */
1811 static int pkt_set_write_settings(struct pktcdvd_device *pd)
1812 {
1813         struct packet_command cgc;
1814         struct request_sense sense;
1815         write_param_page *wp;
1816         char buffer[128];
1817         int ret, size;
1818
1819         /* doesn't apply to DVD+RW or DVD-RAM */
1820         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1821                 return 0;
1822
1823         memset(buffer, 0, sizeof(buffer));
1824         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1825         cgc.sense = &sense;
1826         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1827                 pkt_dump_sense(&cgc);
1828                 return ret;
1829         }
1830
1831         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1832         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1833         if (size > sizeof(buffer))
1834                 size = sizeof(buffer);
1835
1836         /*
1837          * now get it all
1838          */
1839         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1840         cgc.sense = &sense;
1841         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1842                 pkt_dump_sense(&cgc);
1843                 return ret;
1844         }
1845
1846         /*
1847          * write page is offset header + block descriptor length
1848          */
1849         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1850
1851         wp->fp = pd->settings.fp;
1852         wp->track_mode = pd->settings.track_mode;
1853         wp->write_type = pd->settings.write_type;
1854         wp->data_block_type = pd->settings.block_mode;
1855
1856         wp->multi_session = 0;
1857
1858 #ifdef PACKET_USE_LS
1859         wp->link_size = 7;
1860         wp->ls_v = 1;
1861 #endif
1862
1863         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1864                 wp->session_format = 0;
1865                 wp->subhdr2 = 0x20;
1866         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1867                 wp->session_format = 0x20;
1868                 wp->subhdr2 = 8;
1869 #if 0
1870                 wp->mcn[0] = 0x80;
1871                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1872 #endif
1873         } else {
1874                 /*
1875                  * paranoia
1876                  */
1877                 printk(DRIVER_NAME": write mode wrong %d\n", wp->data_block_type);
1878                 return 1;
1879         }
1880         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1881
1882         cgc.buflen = cgc.cmd[8] = size;
1883         if ((ret = pkt_mode_select(pd, &cgc))) {
1884                 pkt_dump_sense(&cgc);
1885                 return ret;
1886         }
1887
1888         pkt_print_settings(pd);
1889         return 0;
1890 }
1891
1892 /*
1893  * 1 -- we can write to this track, 0 -- we can't
1894  */
1895 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1896 {
1897         switch (pd->mmc3_profile) {
1898                 case 0x1a: /* DVD+RW */
1899                 case 0x12: /* DVD-RAM */
1900                         /* The track is always writable on DVD+RW/DVD-RAM */
1901                         return 1;
1902                 default:
1903                         break;
1904         }
1905
1906         if (!ti->packet || !ti->fp)
1907                 return 0;
1908
1909         /*
1910          * "good" settings as per Mt Fuji.
1911          */
1912         if (ti->rt == 0 && ti->blank == 0)
1913                 return 1;
1914
1915         if (ti->rt == 0 && ti->blank == 1)
1916                 return 1;
1917
1918         if (ti->rt == 1 && ti->blank == 0)
1919                 return 1;
1920
1921         printk(DRIVER_NAME": bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1922         return 0;
1923 }
1924
1925 /*
1926  * 1 -- we can write to this disc, 0 -- we can't
1927  */
1928 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1929 {
1930         switch (pd->mmc3_profile) {
1931                 case 0x0a: /* CD-RW */
1932                 case 0xffff: /* MMC3 not supported */
1933                         break;
1934                 case 0x1a: /* DVD+RW */
1935                 case 0x13: /* DVD-RW */
1936                 case 0x12: /* DVD-RAM */
1937                         return 1;
1938                 default:
1939                         VPRINTK(DRIVER_NAME": Wrong disc profile (%x)\n", pd->mmc3_profile);
1940                         return 0;
1941         }
1942
1943         /*
1944          * for disc type 0xff we should probably reserve a new track.
1945          * but i'm not sure, should we leave this to user apps? probably.
1946          */
1947         if (di->disc_type == 0xff) {
1948                 printk(DRIVER_NAME": Unknown disc. No track?\n");
1949                 return 0;
1950         }
1951
1952         if (di->disc_type != 0x20 && di->disc_type != 0) {
1953                 printk(DRIVER_NAME": Wrong disc type (%x)\n", di->disc_type);
1954                 return 0;
1955         }
1956
1957         if (di->erasable == 0) {
1958                 printk(DRIVER_NAME": Disc not erasable\n");
1959                 return 0;
1960         }
1961
1962         if (di->border_status == PACKET_SESSION_RESERVED) {
1963                 printk(DRIVER_NAME": Can't write to last track (reserved)\n");
1964                 return 0;
1965         }
1966
1967         return 1;
1968 }
1969
1970 static int pkt_probe_settings(struct pktcdvd_device *pd)
1971 {
1972         struct packet_command cgc;
1973         unsigned char buf[12];
1974         disc_information di;
1975         track_information ti;
1976         int ret, track;
1977
1978         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1979         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1980         cgc.cmd[8] = 8;
1981         ret = pkt_generic_packet(pd, &cgc);
1982         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1983
1984         memset(&di, 0, sizeof(disc_information));
1985         memset(&ti, 0, sizeof(track_information));
1986
1987         if ((ret = pkt_get_disc_info(pd, &di))) {
1988                 printk("failed get_disc\n");
1989                 return ret;
1990         }
1991
1992         if (!pkt_writable_disc(pd, &di))
1993                 return -EROFS;
1994
1995         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1996
1997         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1998         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1999                 printk(DRIVER_NAME": failed get_track\n");
2000                 return ret;
2001         }
2002
2003         if (!pkt_writable_track(pd, &ti)) {
2004                 printk(DRIVER_NAME": can't write to this track\n");
2005                 return -EROFS;
2006         }
2007
2008         /*
2009          * we keep packet size in 512 byte units, makes it easier to
2010          * deal with request calculations.
2011          */
2012         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
2013         if (pd->settings.size == 0) {
2014                 printk(DRIVER_NAME": detected zero packet size!\n");
2015                 return -ENXIO;
2016         }
2017         if (pd->settings.size > PACKET_MAX_SECTORS) {
2018                 printk(DRIVER_NAME": packet size is too big\n");
2019                 return -EROFS;
2020         }
2021         pd->settings.fp = ti.fp;
2022         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
2023
2024         if (ti.nwa_v) {
2025                 pd->nwa = be32_to_cpu(ti.next_writable);
2026                 set_bit(PACKET_NWA_VALID, &pd->flags);
2027         }
2028
2029         /*
2030          * in theory we could use lra on -RW media as well and just zero
2031          * blocks that haven't been written yet, but in practice that
2032          * is just a no-go. we'll use that for -R, naturally.
2033          */
2034         if (ti.lra_v) {
2035                 pd->lra = be32_to_cpu(ti.last_rec_address);
2036                 set_bit(PACKET_LRA_VALID, &pd->flags);
2037         } else {
2038                 pd->lra = 0xffffffff;
2039                 set_bit(PACKET_LRA_VALID, &pd->flags);
2040         }
2041
2042         /*
2043          * fine for now
2044          */
2045         pd->settings.link_loss = 7;
2046         pd->settings.write_type = 0;    /* packet */
2047         pd->settings.track_mode = ti.track_mode;
2048
2049         /*
2050          * mode1 or mode2 disc
2051          */
2052         switch (ti.data_mode) {
2053                 case PACKET_MODE1:
2054                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
2055                         break;
2056                 case PACKET_MODE2:
2057                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
2058                         break;
2059                 default:
2060                         printk(DRIVER_NAME": unknown data mode\n");
2061                         return -EROFS;
2062         }
2063         return 0;
2064 }
2065
2066 /*
2067  * enable/disable write caching on drive
2068  */
2069 static int pkt_write_caching(struct pktcdvd_device *pd, int set)
2070 {
2071         struct packet_command cgc;
2072         struct request_sense sense;
2073         unsigned char buf[64];
2074         int ret;
2075
2076         memset(buf, 0, sizeof(buf));
2077         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
2078         cgc.sense = &sense;
2079         cgc.buflen = pd->mode_offset + 12;
2080
2081         /*
2082          * caching mode page might not be there, so quiet this command
2083          */
2084         cgc.quiet = 1;
2085
2086         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
2087                 return ret;
2088
2089         buf[pd->mode_offset + 10] |= (!!set << 2);
2090
2091         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
2092         ret = pkt_mode_select(pd, &cgc);
2093         if (ret) {
2094                 printk(DRIVER_NAME": write caching control failed\n");
2095                 pkt_dump_sense(&cgc);
2096         } else if (!ret && set)
2097                 printk(DRIVER_NAME": enabled write caching on %s\n", pd->name);
2098         return ret;
2099 }
2100
2101 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
2102 {
2103         struct packet_command cgc;
2104
2105         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2106         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
2107         cgc.cmd[4] = lockflag ? 1 : 0;
2108         return pkt_generic_packet(pd, &cgc);
2109 }
2110
2111 /*
2112  * Returns drive maximum write speed
2113  */
2114 static int pkt_get_max_speed(struct pktcdvd_device *pd, unsigned *write_speed)
2115 {
2116         struct packet_command cgc;
2117         struct request_sense sense;
2118         unsigned char buf[256+18];
2119         unsigned char *cap_buf;
2120         int ret, offset;
2121
2122         memset(buf, 0, sizeof(buf));
2123         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
2124         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
2125         cgc.sense = &sense;
2126
2127         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2128         if (ret) {
2129                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2130                              sizeof(struct mode_page_header);
2131                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2132                 if (ret) {
2133                         pkt_dump_sense(&cgc);
2134                         return ret;
2135                 }
2136         }
2137
2138         offset = 20;                        /* Obsoleted field, used by older drives */
2139         if (cap_buf[1] >= 28)
2140                 offset = 28;                /* Current write speed selected */
2141         if (cap_buf[1] >= 30) {
2142                 /* If the drive reports at least one "Logical Unit Write
2143                  * Speed Performance Descriptor Block", use the information
2144                  * in the first block. (contains the highest speed)
2145                  */
2146                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2147                 if (num_spdb > 0)
2148                         offset = 34;
2149         }
2150
2151         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2152         return 0;
2153 }
2154
2155 /* These tables from cdrecord - I don't have orange book */
2156 /* standard speed CD-RW (1-4x) */
2157 static char clv_to_speed[16] = {
2158         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2159            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2160 };
2161 /* high speed CD-RW (-10x) */
2162 static char hs_clv_to_speed[16] = {
2163         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2164            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2165 };
2166 /* ultra high speed CD-RW */
2167 static char us_clv_to_speed[16] = {
2168         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2169            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2170 };
2171
2172 /*
2173  * reads the maximum media speed from ATIP
2174  */
2175 static int pkt_media_speed(struct pktcdvd_device *pd, unsigned *speed)
2176 {
2177         struct packet_command cgc;
2178         struct request_sense sense;
2179         unsigned char buf[64];
2180         unsigned int size, st, sp;
2181         int ret;
2182
2183         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2184         cgc.sense = &sense;
2185         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2186         cgc.cmd[1] = 2;
2187         cgc.cmd[2] = 4; /* READ ATIP */
2188         cgc.cmd[8] = 2;
2189         ret = pkt_generic_packet(pd, &cgc);
2190         if (ret) {
2191                 pkt_dump_sense(&cgc);
2192                 return ret;
2193         }
2194         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2195         if (size > sizeof(buf))
2196                 size = sizeof(buf);
2197
2198         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2199         cgc.sense = &sense;
2200         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2201         cgc.cmd[1] = 2;
2202         cgc.cmd[2] = 4;
2203         cgc.cmd[8] = size;
2204         ret = pkt_generic_packet(pd, &cgc);
2205         if (ret) {
2206                 pkt_dump_sense(&cgc);
2207                 return ret;
2208         }
2209
2210         if (!buf[6] & 0x40) {
2211                 printk(DRIVER_NAME": Disc type is not CD-RW\n");
2212                 return 1;
2213         }
2214         if (!buf[6] & 0x4) {
2215                 printk(DRIVER_NAME": A1 values on media are not valid, maybe not CDRW?\n");
2216                 return 1;
2217         }
2218
2219         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2220
2221         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2222
2223         /* Info from cdrecord */
2224         switch (st) {
2225                 case 0: /* standard speed */
2226                         *speed = clv_to_speed[sp];
2227                         break;
2228                 case 1: /* high speed */
2229                         *speed = hs_clv_to_speed[sp];
2230                         break;
2231                 case 2: /* ultra high speed */
2232                         *speed = us_clv_to_speed[sp];
2233                         break;
2234                 default:
2235                         printk(DRIVER_NAME": Unknown disc sub-type %d\n",st);
2236                         return 1;
2237         }
2238         if (*speed) {
2239                 printk(DRIVER_NAME": Max. media speed: %d\n",*speed);
2240                 return 0;
2241         } else {
2242                 printk(DRIVER_NAME": Unknown speed %d for sub-type %d\n",sp,st);
2243                 return 1;
2244         }
2245 }
2246
2247 static int pkt_perform_opc(struct pktcdvd_device *pd)
2248 {
2249         struct packet_command cgc;
2250         struct request_sense sense;
2251         int ret;
2252
2253         VPRINTK(DRIVER_NAME": Performing OPC\n");
2254
2255         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2256         cgc.sense = &sense;
2257         cgc.timeout = 60*HZ;
2258         cgc.cmd[0] = GPCMD_SEND_OPC;
2259         cgc.cmd[1] = 1;
2260         if ((ret = pkt_generic_packet(pd, &cgc)))
2261                 pkt_dump_sense(&cgc);
2262         return ret;
2263 }
2264
2265 static int pkt_open_write(struct pktcdvd_device *pd)
2266 {
2267         int ret;
2268         unsigned int write_speed, media_write_speed, read_speed;
2269
2270         if ((ret = pkt_probe_settings(pd))) {
2271                 VPRINTK(DRIVER_NAME": %s failed probe\n", pd->name);
2272                 return ret;
2273         }
2274
2275         if ((ret = pkt_set_write_settings(pd))) {
2276                 DPRINTK(DRIVER_NAME": %s failed saving write settings\n", pd->name);
2277                 return -EIO;
2278         }
2279
2280         pkt_write_caching(pd, USE_WCACHING);
2281
2282         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2283                 write_speed = 16 * 177;
2284         switch (pd->mmc3_profile) {
2285                 case 0x13: /* DVD-RW */
2286                 case 0x1a: /* DVD+RW */
2287                 case 0x12: /* DVD-RAM */
2288                         DPRINTK(DRIVER_NAME": write speed %ukB/s\n", write_speed);
2289                         break;
2290                 default:
2291                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2292                                 media_write_speed = 16;
2293                         write_speed = min(write_speed, media_write_speed * 177);
2294                         DPRINTK(DRIVER_NAME": write speed %ux\n", write_speed / 176);
2295                         break;
2296         }
2297         read_speed = write_speed;
2298
2299         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2300                 DPRINTK(DRIVER_NAME": %s couldn't set write speed\n", pd->name);
2301                 return -EIO;
2302         }
2303         pd->write_speed = write_speed;
2304         pd->read_speed = read_speed;
2305
2306         if ((ret = pkt_perform_opc(pd))) {
2307                 DPRINTK(DRIVER_NAME": %s Optimum Power Calibration failed\n", pd->name);
2308         }
2309
2310         return 0;
2311 }
2312
2313 /*
2314  * called at open time.
2315  */
2316 static int pkt_open_dev(struct pktcdvd_device *pd, int write)
2317 {
2318         int ret;
2319         long lba;
2320         request_queue_t *q;
2321
2322         /*
2323          * We need to re-open the cdrom device without O_NONBLOCK to be able
2324          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2325          * so bdget() can't fail.
2326          */
2327         bdget(pd->bdev->bd_dev);
2328         if ((ret = blkdev_get(pd->bdev, FMODE_READ, O_RDONLY)))
2329                 goto out;
2330
2331         if ((ret = bd_claim(pd->bdev, pd)))
2332                 goto out_putdev;
2333
2334         if ((ret = pkt_get_last_written(pd, &lba))) {
2335                 printk(DRIVER_NAME": pkt_get_last_written failed\n");
2336                 goto out_unclaim;
2337         }
2338
2339         set_capacity(pd->disk, lba << 2);
2340         set_capacity(pd->bdev->bd_disk, lba << 2);
2341         bd_set_size(pd->bdev, (loff_t)lba << 11);
2342
2343         q = bdev_get_queue(pd->bdev);
2344         if (write) {
2345                 if ((ret = pkt_open_write(pd)))
2346                         goto out_unclaim;
2347                 /*
2348                  * Some CDRW drives can not handle writes larger than one packet,
2349                  * even if the size is a multiple of the packet size.
2350                  */
2351                 spin_lock_irq(q->queue_lock);
2352                 blk_queue_max_sectors(q, pd->settings.size);
2353                 spin_unlock_irq(q->queue_lock);
2354                 set_bit(PACKET_WRITABLE, &pd->flags);
2355         } else {
2356                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2357                 clear_bit(PACKET_WRITABLE, &pd->flags);
2358         }
2359
2360         if ((ret = pkt_set_segment_merging(pd, q)))
2361                 goto out_unclaim;
2362
2363         if (write) {
2364                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2365                         printk(DRIVER_NAME": not enough memory for buffers\n");
2366                         ret = -ENOMEM;
2367                         goto out_unclaim;
2368                 }
2369                 printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
2370         }
2371
2372         return 0;
2373
2374 out_unclaim:
2375         bd_release(pd->bdev);
2376 out_putdev:
2377         blkdev_put(pd->bdev);
2378 out:
2379         return ret;
2380 }
2381
2382 /*
2383  * called when the device is closed. makes sure that the device flushes
2384  * the internal cache before we close.
2385  */
2386 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2387 {
2388         if (flush && pkt_flush_cache(pd))
2389                 DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
2390
2391         pkt_lock_door(pd, 0);
2392
2393         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2394         bd_release(pd->bdev);
2395         blkdev_put(pd->bdev);
2396
2397         pkt_shrink_pktlist(pd);
2398 }
2399
2400 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
2401 {
2402         if (dev_minor >= MAX_WRITERS)
2403                 return NULL;
2404         return pkt_devs[dev_minor];
2405 }
2406
2407 static int pkt_open(struct inode *inode, struct file *file)
2408 {
2409         struct pktcdvd_device *pd = NULL;
2410         int ret;
2411
2412         VPRINTK(DRIVER_NAME": entering open\n");
2413
2414         mutex_lock(&ctl_mutex);
2415         pd = pkt_find_dev_from_minor(iminor(inode));
2416         if (!pd) {
2417                 ret = -ENODEV;
2418                 goto out;
2419         }
2420         BUG_ON(pd->refcnt < 0);
2421
2422         pd->refcnt++;
2423         if (pd->refcnt > 1) {
2424                 if ((file->f_mode & FMODE_WRITE) &&
2425                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2426                         ret = -EBUSY;
2427                         goto out_dec;
2428                 }
2429         } else {
2430                 ret = pkt_open_dev(pd, file->f_mode & FMODE_WRITE);
2431                 if (ret)
2432                         goto out_dec;
2433                 /*
2434                  * needed here as well, since ext2 (among others) may change
2435                  * the blocksize at mount time
2436                  */
2437                 set_blocksize(inode->i_bdev, CD_FRAMESIZE);
2438         }
2439
2440         mutex_unlock(&ctl_mutex);
2441         return 0;
2442
2443 out_dec:
2444         pd->refcnt--;
2445 out:
2446         VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
2447         mutex_unlock(&ctl_mutex);
2448         return ret;
2449 }
2450
2451 static int pkt_close(struct inode *inode, struct file *file)
2452 {
2453         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2454         int ret = 0;
2455
2456         mutex_lock(&ctl_mutex);
2457         pd->refcnt--;
2458         BUG_ON(pd->refcnt < 0);
2459         if (pd->refcnt == 0) {
2460                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2461                 pkt_release_dev(pd, flush);
2462         }
2463         mutex_unlock(&ctl_mutex);
2464         return ret;
2465 }
2466
2467
2468 static int pkt_end_io_read_cloned(struct bio *bio, unsigned int bytes_done, int err)
2469 {
2470         struct packet_stacked_data *psd = bio->bi_private;
2471         struct pktcdvd_device *pd = psd->pd;
2472
2473         if (bio->bi_size)
2474                 return 1;
2475
2476         bio_put(bio);
2477         bio_endio(psd->bio, psd->bio->bi_size, err);
2478         mempool_free(psd, psd_pool);
2479         pkt_bio_finished(pd);
2480         return 0;
2481 }
2482
2483 static int pkt_make_request(request_queue_t *q, struct bio *bio)
2484 {
2485         struct pktcdvd_device *pd;
2486         char b[BDEVNAME_SIZE];
2487         sector_t zone;
2488         struct packet_data *pkt;
2489         int was_empty, blocked_bio;
2490         struct pkt_rb_node *node;
2491
2492         pd = q->queuedata;
2493         if (!pd) {
2494                 printk(DRIVER_NAME": %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
2495                 goto end_io;
2496         }
2497
2498         /*
2499          * Clone READ bios so we can have our own bi_end_io callback.
2500          */
2501         if (bio_data_dir(bio) == READ) {
2502                 struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2503                 struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2504
2505                 psd->pd = pd;
2506                 psd->bio = bio;
2507                 cloned_bio->bi_bdev = pd->bdev;
2508                 cloned_bio->bi_private = psd;
2509                 cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2510                 pd->stats.secs_r += bio->bi_size >> 9;
2511                 pkt_queue_bio(pd, cloned_bio);
2512                 return 0;
2513         }
2514
2515         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2516                 printk(DRIVER_NAME": WRITE for ro device %s (%llu)\n",
2517                         pd->name, (unsigned long long)bio->bi_sector);
2518                 goto end_io;
2519         }
2520
2521         if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
2522                 printk(DRIVER_NAME": wrong bio size\n");
2523                 goto end_io;
2524         }
2525
2526         blk_queue_bounce(q, &bio);
2527
2528         zone = ZONE(bio->bi_sector, pd);
2529         VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
2530                 (unsigned long long)bio->bi_sector,
2531                 (unsigned long long)(bio->bi_sector + bio_sectors(bio)));
2532
2533         /* Check if we have to split the bio */
2534         {
2535                 struct bio_pair *bp;
2536                 sector_t last_zone;
2537                 int first_sectors;
2538
2539                 last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
2540                 if (last_zone != zone) {
2541                         BUG_ON(last_zone != zone + pd->settings.size);
2542                         first_sectors = last_zone - bio->bi_sector;
2543                         bp = bio_split(bio, bio_split_pool, first_sectors);
2544                         BUG_ON(!bp);
2545                         pkt_make_request(q, &bp->bio1);
2546                         pkt_make_request(q, &bp->bio2);
2547                         bio_pair_release(bp);
2548                         return 0;
2549                 }
2550         }
2551
2552         /*
2553          * If we find a matching packet in state WAITING or READ_WAIT, we can
2554          * just append this bio to that packet.
2555          */
2556         spin_lock(&pd->cdrw.active_list_lock);
2557         blocked_bio = 0;
2558         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2559                 if (pkt->sector == zone) {
2560                         spin_lock(&pkt->lock);
2561                         if ((pkt->state == PACKET_WAITING_STATE) ||
2562                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2563                                 pkt_add_list_last(bio, &pkt->orig_bios,
2564                                                   &pkt->orig_bios_tail);
2565                                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
2566                                 if ((pkt->write_size >= pkt->frames) &&
2567                                     (pkt->state == PACKET_WAITING_STATE)) {
2568                                         atomic_inc(&pkt->run_sm);
2569                                         wake_up(&pd->wqueue);
2570                                 }
2571                                 spin_unlock(&pkt->lock);
2572                                 spin_unlock(&pd->cdrw.active_list_lock);
2573                                 return 0;
2574                         } else {
2575                                 blocked_bio = 1;
2576                         }
2577                         spin_unlock(&pkt->lock);
2578                 }
2579         }
2580         spin_unlock(&pd->cdrw.active_list_lock);
2581
2582         /*
2583          * Test if there is enough room left in the bio work queue
2584          * (queue size >= congestion on mark).
2585          * If not, wait till the work queue size is below the congestion off mark.
2586          */
2587         spin_lock(&pd->lock);
2588         if (pd->write_congestion_on > 0
2589             && pd->bio_queue_size >= pd->write_congestion_on) {
2590                 set_bdi_congested(&q->backing_dev_info, WRITE);
2591                 do {
2592                         spin_unlock(&pd->lock);
2593                         congestion_wait(WRITE, HZ);
2594                         spin_lock(&pd->lock);
2595                 } while(pd->bio_queue_size > pd->write_congestion_off);
2596         }
2597         spin_unlock(&pd->lock);
2598
2599         /*
2600          * No matching packet found. Store the bio in the work queue.
2601          */
2602         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2603         node->bio = bio;
2604         spin_lock(&pd->lock);
2605         BUG_ON(pd->bio_queue_size < 0);
2606         was_empty = (pd->bio_queue_size == 0);
2607         pkt_rbtree_insert(pd, node);
2608         spin_unlock(&pd->lock);
2609
2610         /*
2611          * Wake up the worker thread.
2612          */
2613         atomic_set(&pd->scan_queue, 1);
2614         if (was_empty) {
2615                 /* This wake_up is required for correct operation */
2616                 wake_up(&pd->wqueue);
2617         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2618                 /*
2619                  * This wake up is not required for correct operation,
2620                  * but improves performance in some cases.
2621                  */
2622                 wake_up(&pd->wqueue);
2623         }
2624         return 0;
2625 end_io:
2626         bio_io_error(bio, bio->bi_size);
2627         return 0;
2628 }
2629
2630
2631
2632 static int pkt_merge_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *bvec)
2633 {
2634         struct pktcdvd_device *pd = q->queuedata;
2635         sector_t zone = ZONE(bio->bi_sector, pd);
2636         int used = ((bio->bi_sector - zone) << 9) + bio->bi_size;
2637         int remaining = (pd->settings.size << 9) - used;
2638         int remaining2;
2639
2640         /*
2641          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2642          * boundary, pkt_make_request() will split the bio.
2643          */
2644         remaining2 = PAGE_SIZE - bio->bi_size;
2645         remaining = max(remaining, remaining2);
2646
2647         BUG_ON(remaining < 0);
2648         return remaining;
2649 }
2650
2651 static void pkt_init_queue(struct pktcdvd_device *pd)
2652 {
2653         request_queue_t *q = pd->disk->queue;
2654
2655         blk_queue_make_request(q, pkt_make_request);
2656         blk_queue_hardsect_size(q, CD_FRAMESIZE);
2657         blk_queue_max_sectors(q, PACKET_MAX_SECTORS);
2658         blk_queue_merge_bvec(q, pkt_merge_bvec);
2659         q->queuedata = pd;
2660 }
2661
2662 static int pkt_seq_show(struct seq_file *m, void *p)
2663 {
2664         struct pktcdvd_device *pd = m->private;
2665         char *msg;
2666         char bdev_buf[BDEVNAME_SIZE];
2667         int states[PACKET_NUM_STATES];
2668
2669         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2670                    bdevname(pd->bdev, bdev_buf));
2671
2672         seq_printf(m, "\nSettings:\n");
2673         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2674
2675         if (pd->settings.write_type == 0)
2676                 msg = "Packet";
2677         else
2678                 msg = "Unknown";
2679         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2680
2681         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2682         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2683
2684         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2685
2686         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2687                 msg = "Mode 1";
2688         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2689                 msg = "Mode 2";
2690         else
2691                 msg = "Unknown";
2692         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2693
2694         seq_printf(m, "\nStatistics:\n");
2695         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2696         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2697         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2698         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2699         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2700
2701         seq_printf(m, "\nMisc:\n");
2702         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2703         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2704         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2705         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2706         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2707         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2708
2709         seq_printf(m, "\nQueue state:\n");
2710         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2711         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2712         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2713
2714         pkt_count_states(pd, states);
2715         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2716                    states[0], states[1], states[2], states[3], states[4], states[5]);
2717
2718         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2719                         pd->write_congestion_off,
2720                         pd->write_congestion_on);
2721         return 0;
2722 }
2723
2724 static int pkt_seq_open(struct inode *inode, struct file *file)
2725 {
2726         return single_open(file, pkt_seq_show, PDE(inode)->data);
2727 }
2728
2729 static const struct file_operations pkt_proc_fops = {
2730         .open   = pkt_seq_open,
2731         .read   = seq_read,
2732         .llseek = seq_lseek,
2733         .release = single_release
2734 };
2735
2736 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2737 {
2738         int i;
2739         int ret = 0;
2740         char b[BDEVNAME_SIZE];
2741         struct proc_dir_entry *proc;
2742         struct block_device *bdev;
2743
2744         if (pd->pkt_dev == dev) {
2745                 printk(DRIVER_NAME": Recursive setup not allowed\n");
2746                 return -EBUSY;
2747         }
2748         for (i = 0; i < MAX_WRITERS; i++) {
2749                 struct pktcdvd_device *pd2 = pkt_devs[i];
2750                 if (!pd2)
2751                         continue;
2752                 if (pd2->bdev->bd_dev == dev) {
2753                         printk(DRIVER_NAME": %s already setup\n", bdevname(pd2->bdev, b));
2754                         return -EBUSY;
2755                 }
2756                 if (pd2->pkt_dev == dev) {
2757                         printk(DRIVER_NAME": Can't chain pktcdvd devices\n");
2758                         return -EBUSY;
2759                 }
2760         }
2761
2762         bdev = bdget(dev);
2763         if (!bdev)
2764                 return -ENOMEM;
2765         ret = blkdev_get(bdev, FMODE_READ, O_RDONLY | O_NONBLOCK);
2766         if (ret)
2767                 return ret;
2768
2769         /* This is safe, since we have a reference from open(). */
2770         __module_get(THIS_MODULE);
2771
2772         pd->bdev = bdev;
2773         set_blocksize(bdev, CD_FRAMESIZE);
2774
2775         pkt_init_queue(pd);
2776
2777         atomic_set(&pd->cdrw.pending_bios, 0);
2778         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2779         if (IS_ERR(pd->cdrw.thread)) {
2780                 printk(DRIVER_NAME": can't start kernel thread\n");
2781                 ret = -ENOMEM;
2782                 goto out_mem;
2783         }
2784
2785         proc = create_proc_entry(pd->name, 0, pkt_proc);
2786         if (proc) {
2787                 proc->data = pd;
2788                 proc->proc_fops = &pkt_proc_fops;
2789         }
2790         DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
2791         return 0;
2792
2793 out_mem:
2794         blkdev_put(bdev);
2795         /* This is safe: open() is still holding a reference. */
2796         module_put(THIS_MODULE);
2797         return ret;
2798 }
2799
2800 static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
2801 {
2802         struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
2803
2804         VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd, imajor(inode), iminor(inode));
2805
2806         switch (cmd) {
2807         /*
2808          * forward selected CDROM ioctls to CD-ROM, for UDF
2809          */
2810         case CDROMMULTISESSION:
2811         case CDROMREADTOCENTRY:
2812         case CDROM_LAST_WRITTEN:
2813         case CDROM_SEND_PACKET:
2814         case SCSI_IOCTL_SEND_COMMAND:
2815                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2816
2817         case CDROMEJECT:
2818                 /*
2819                  * The door gets locked when the device is opened, so we
2820                  * have to unlock it or else the eject command fails.
2821                  */
2822                 if (pd->refcnt == 1)
2823                         pkt_lock_door(pd, 0);
2824                 return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
2825
2826         default:
2827                 VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, cmd);
2828                 return -ENOTTY;
2829         }
2830
2831         return 0;
2832 }
2833
2834 static int pkt_media_changed(struct gendisk *disk)
2835 {
2836         struct pktcdvd_device *pd = disk->private_data;
2837         struct gendisk *attached_disk;
2838
2839         if (!pd)
2840                 return 0;
2841         if (!pd->bdev)
2842                 return 0;
2843         attached_disk = pd->bdev->bd_disk;
2844         if (!attached_disk)
2845                 return 0;
2846         return attached_disk->fops->media_changed(attached_disk);
2847 }
2848
2849 static struct block_device_operations pktcdvd_ops = {
2850         .owner =                THIS_MODULE,
2851         .open =                 pkt_open,
2852         .release =              pkt_close,
2853         .ioctl =                pkt_ioctl,
2854         .media_changed =        pkt_media_changed,
2855 };
2856
2857 /*
2858  * Set up mapping from pktcdvd device to CD-ROM device.
2859  */
2860 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2861 {
2862         int idx;
2863         int ret = -ENOMEM;
2864         struct pktcdvd_device *pd;
2865         struct gendisk *disk;
2866
2867         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2868
2869         for (idx = 0; idx < MAX_WRITERS; idx++)
2870                 if (!pkt_devs[idx])
2871                         break;
2872         if (idx == MAX_WRITERS) {
2873                 printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
2874                 ret = -EBUSY;
2875                 goto out_mutex;
2876         }
2877
2878         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2879         if (!pd)
2880                 goto out_mutex;
2881
2882         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2883                                                   sizeof(struct pkt_rb_node));
2884         if (!pd->rb_pool)
2885                 goto out_mem;
2886
2887         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2888         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2889         spin_lock_init(&pd->cdrw.active_list_lock);
2890
2891         spin_lock_init(&pd->lock);
2892         spin_lock_init(&pd->iosched.lock);
2893         sprintf(pd->name, DRIVER_NAME"%d", idx);
2894         init_waitqueue_head(&pd->wqueue);
2895         pd->bio_queue = RB_ROOT;
2896
2897         pd->write_congestion_on  = write_congestion_on;
2898         pd->write_congestion_off = write_congestion_off;
2899
2900         disk = alloc_disk(1);
2901         if (!disk)
2902                 goto out_mem;
2903         pd->disk = disk;
2904         disk->major = pktdev_major;
2905         disk->first_minor = idx;
2906         disk->fops = &pktcdvd_ops;
2907         disk->flags = GENHD_FL_REMOVABLE;
2908         strcpy(disk->disk_name, pd->name);
2909         disk->private_data = pd;
2910         disk->queue = blk_alloc_queue(GFP_KERNEL);
2911         if (!disk->queue)
2912                 goto out_mem2;
2913
2914         pd->pkt_dev = MKDEV(disk->major, disk->first_minor);
2915         ret = pkt_new_dev(pd, dev);
2916         if (ret)
2917                 goto out_new_dev;
2918
2919         add_disk(disk);
2920
2921         pkt_sysfs_dev_new(pd);
2922         pkt_debugfs_dev_new(pd);
2923
2924         pkt_devs[idx] = pd;
2925         if (pkt_dev)
2926                 *pkt_dev = pd->pkt_dev;
2927
2928         mutex_unlock(&ctl_mutex);
2929         return 0;
2930
2931 out_new_dev:
2932         blk_cleanup_queue(disk->queue);
2933 out_mem2:
2934         put_disk(disk);
2935 out_mem:
2936         if (pd->rb_pool)
2937                 mempool_destroy(pd->rb_pool);
2938         kfree(pd);
2939 out_mutex:
2940         mutex_unlock(&ctl_mutex);
2941         printk(DRIVER_NAME": setup of pktcdvd device failed\n");
2942         return ret;
2943 }
2944
2945 /*
2946  * Tear down mapping from pktcdvd device to CD-ROM device.
2947  */
2948 static int pkt_remove_dev(dev_t pkt_dev)
2949 {
2950         struct pktcdvd_device *pd;
2951         int idx;
2952         int ret = 0;
2953
2954         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2955
2956         for (idx = 0; idx < MAX_WRITERS; idx++) {
2957                 pd = pkt_devs[idx];
2958                 if (pd && (pd->pkt_dev == pkt_dev))
2959                         break;
2960         }
2961         if (idx == MAX_WRITERS) {
2962                 DPRINTK(DRIVER_NAME": dev not setup\n");
2963                 ret = -ENXIO;
2964                 goto out;
2965         }
2966
2967         if (pd->refcnt > 0) {
2968                 ret = -EBUSY;
2969                 goto out;
2970         }
2971         if (!IS_ERR(pd->cdrw.thread))
2972                 kthread_stop(pd->cdrw.thread);
2973
2974         pkt_devs[idx] = NULL;
2975
2976         pkt_debugfs_dev_remove(pd);
2977         pkt_sysfs_dev_remove(pd);
2978
2979         blkdev_put(pd->bdev);
2980
2981         remove_proc_entry(pd->name, pkt_proc);
2982         DPRINTK(DRIVER_NAME": writer %s unmapped\n", pd->name);
2983
2984         del_gendisk(pd->disk);
2985         blk_cleanup_queue(pd->disk->queue);
2986         put_disk(pd->disk);
2987
2988         mempool_destroy(pd->rb_pool);
2989         kfree(pd);
2990
2991         /* This is safe: open() is still holding a reference. */
2992         module_put(THIS_MODULE);
2993
2994 out:
2995         mutex_unlock(&ctl_mutex);
2996         return ret;
2997 }
2998
2999 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
3000 {
3001         struct pktcdvd_device *pd;
3002
3003         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3004
3005         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
3006         if (pd) {
3007                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
3008                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
3009         } else {
3010                 ctrl_cmd->dev = 0;
3011                 ctrl_cmd->pkt_dev = 0;
3012         }
3013         ctrl_cmd->num_devices = MAX_WRITERS;
3014
3015         mutex_unlock(&ctl_mutex);
3016 }
3017
3018 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
3019 {
3020         void __user *argp = (void __user *)arg;
3021         struct pkt_ctrl_command ctrl_cmd;
3022         int ret = 0;
3023         dev_t pkt_dev = 0;
3024
3025         if (cmd != PACKET_CTRL_CMD)
3026                 return -ENOTTY;
3027
3028         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
3029                 return -EFAULT;
3030
3031         switch (ctrl_cmd.command) {
3032         case PKT_CTRL_CMD_SETUP:
3033                 if (!capable(CAP_SYS_ADMIN))
3034                         return -EPERM;
3035                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
3036                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
3037                 break;
3038         case PKT_CTRL_CMD_TEARDOWN:
3039                 if (!capable(CAP_SYS_ADMIN))
3040                         return -EPERM;
3041                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
3042                 break;
3043         case PKT_CTRL_CMD_STATUS:
3044                 pkt_get_status(&ctrl_cmd);
3045                 break;
3046         default:
3047                 return -ENOTTY;
3048         }
3049
3050         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
3051                 return -EFAULT;
3052         return ret;
3053 }
3054
3055
3056 static const struct file_operations pkt_ctl_fops = {
3057         .ioctl   = pkt_ctl_ioctl,
3058         .owner   = THIS_MODULE,
3059 };
3060
3061 static struct miscdevice pkt_misc = {
3062         .minor          = MISC_DYNAMIC_MINOR,
3063         .name           = DRIVER_NAME,
3064         .fops           = &pkt_ctl_fops
3065 };
3066
3067 static int __init pkt_init(void)
3068 {
3069         int ret;
3070
3071         mutex_init(&ctl_mutex);
3072
3073         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
3074                                         sizeof(struct packet_stacked_data));
3075         if (!psd_pool)
3076                 return -ENOMEM;
3077
3078         ret = register_blkdev(pktdev_major, DRIVER_NAME);
3079         if (ret < 0) {
3080                 printk(DRIVER_NAME": Unable to register block device\n");
3081                 goto out2;
3082         }
3083         if (!pktdev_major)
3084                 pktdev_major = ret;
3085
3086         ret = pkt_sysfs_init();
3087         if (ret)
3088                 goto out;
3089
3090         pkt_debugfs_init();
3091
3092         ret = misc_register(&pkt_misc);
3093         if (ret) {
3094                 printk(DRIVER_NAME": Unable to register misc device\n");
3095                 goto out_misc;
3096         }
3097
3098         pkt_proc = proc_mkdir(DRIVER_NAME, proc_root_driver);
3099
3100         return 0;
3101
3102 out_misc:
3103         pkt_debugfs_cleanup();
3104         pkt_sysfs_cleanup();
3105 out:
3106         unregister_blkdev(pktdev_major, DRIVER_NAME);
3107 out2:
3108         mempool_destroy(psd_pool);
3109         return ret;
3110 }
3111
3112 static void __exit pkt_exit(void)
3113 {
3114         remove_proc_entry(DRIVER_NAME, proc_root_driver);
3115         misc_deregister(&pkt_misc);
3116
3117         pkt_debugfs_cleanup();
3118         pkt_sysfs_cleanup();
3119
3120         unregister_blkdev(pktdev_major, DRIVER_NAME);
3121         mempool_destroy(psd_pool);
3122 }
3123
3124 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3125 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3126 MODULE_LICENSE("GPL");
3127
3128 module_init(pkt_init);
3129 module_exit(pkt_exit);