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