Pileus Git - ~andy/linux/blob - drivers/block/pktcdvd.c

   1 /*
   2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
   3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
   4  * Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
   5  *
   6  * May be copied or modified under the terms of the GNU General Public
   7  * License.  See linux/COPYING for more information.
   8  *
   9  * Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
  10  * DVD-RAM devices.
  11  *
  12  * Theory of operation:
  13  *
  14  * At the lowest level, there is the standard driver for the CD/DVD device,
  15  * typically ide-cd.c or sr.c. This driver can handle read and write requests,
  16  * but it doesn't know anything about the special restrictions that apply to
  17  * packet writing. One restriction is that write requests must be aligned to
  18  * packet boundaries on the physical media, and the size of a write request
  19  * must be equal to the packet size. Another restriction is that a
  20  * GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
  21  * command, if the previous command was a write.
  22  *
  23  * The purpose of the packet writing driver is to hide these restrictions from
  24  * higher layers, such as file systems, and present a block device that can be
  25  * randomly read and written using 2kB-sized blocks.
  26  *
  27  * The lowest layer in the packet writing driver is the packet I/O scheduler.
  28  * Its data is defined by the struct packet_iosched and includes two bio
  29  * queues with pending read and write requests. These queues are processed
  30  * by the pkt_iosched_process_queue() function. The write requests in this
  31  * queue are already properly aligned and sized. This layer is responsible for
  32  * issuing the flush cache commands and scheduling the I/O in a good order.
  33  *
  34  * The next layer transforms unaligned write requests to aligned writes. This
  35  * transformation requires reading missing pieces of data from the underlying
  36  * block device, assembling the pieces to full packets and queuing them to the
  37  * packet I/O scheduler.
  38  *
  39  * At the top layer there is a custom make_request_fn function that forwards
  40  * read requests directly to the iosched queue and puts write requests in the
  41  * unaligned write queue. A kernel thread performs the necessary read
  42  * gathering to convert the unaligned writes to aligned writes and then feeds
  43  * them to the packet I/O scheduler.
  44  *
  45  *************************************************************************/
  46
  47 #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
 708         if (cgc->buflen) {
 709                 if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
 710                         goto out;
 711         }
 712
 713         rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
 714         memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 715
 716         rq->timeout = 60*HZ;
 717         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 718         if (cgc->quiet)
 719                 rq->cmd_flags |= REQ_QUIET;
 720
 721         blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
 722         if (rq->errors)
 723                 ret = -EIO;
 724 out:
 725         blk_put_request(rq);
 726         return ret;
 727 }
 728
 729 static const char *sense_key_string(__u8 index)
 730 {
 731         static const char * const info[] = {
 732                 "No sense", "Recovered error", "Not ready",
 733                 "Medium error", "Hardware error", "Illegal request",
 734                 "Unit attention", "Data protect", "Blank check",
 735         };
 736
 737         return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
 738 }
 739
 740 /*
 741  * A generic sense dump / resolve mechanism should be implemented across
 742  * all ATAPI + SCSI devices.
 743  */
 744 static void pkt_dump_sense(struct pktcdvd_device *pd,
 745                            struct packet_command *cgc)
 746 {
 747         struct request_sense *sense = cgc->sense;
 748
 749         if (sense)
 750                 pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
 751                         CDROM_PACKET_SIZE, cgc->cmd,
 752                         sense->sense_key, sense->asc, sense->ascq,
 753                         sense_key_string(sense->sense_key));
 754         else
 755                 pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
 756 }
 757
 758 /*
 759  * flush the drive cache to media
 760  */
 761 static int pkt_flush_cache(struct pktcdvd_device *pd)
 762 {
 763         struct packet_command cgc;
 764
 765         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 766         cgc.cmd[0] = GPCMD_FLUSH_CACHE;
 767         cgc.quiet = 1;
 768
 769         /*
 770          * the IMMED bit -- we default to not setting it, although that
 771          * would allow a much faster close, this is safer
 772          */
 773 #if 0
 774         cgc.cmd[1] = 1 << 1;
 775 #endif
 776         return pkt_generic_packet(pd, &cgc);
 777 }
 778
 779 /*
 780  * speed is given as the normal factor, e.g. 4 for 4x
 781  */
 782 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 783                                 unsigned write_speed, unsigned read_speed)
 784 {
 785         struct packet_command cgc;
 786         struct request_sense sense;
 787         int ret;
 788
 789         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
 790         cgc.sense = &sense;
 791         cgc.cmd[0] = GPCMD_SET_SPEED;
 792         cgc.cmd[2] = (read_speed >> 8) & 0xff;
 793         cgc.cmd[3] = read_speed & 0xff;
 794         cgc.cmd[4] = (write_speed >> 8) & 0xff;
 795         cgc.cmd[5] = write_speed & 0xff;
 796
 797         if ((ret = pkt_generic_packet(pd, &cgc)))
 798                 pkt_dump_sense(pd, &cgc);
 799
 800         return ret;
 801 }
 802
 803 /*
 804  * Queue a bio for processing by the low-level CD device. Must be called
 805  * from process context.
 806  */
 807 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 808 {
 809         spin_lock(&pd->iosched.lock);
 810         if (bio_data_dir(bio) == READ)
 811                 bio_list_add(&pd->iosched.read_queue, bio);
 812         else
 813                 bio_list_add(&pd->iosched.write_queue, bio);
 814         spin_unlock(&pd->iosched.lock);
 815
 816         atomic_set(&pd->iosched.attention, 1);
 817         wake_up(&pd->wqueue);
 818 }
 819
 820 /*
 821  * Process the queued read/write requests. This function handles special
 822  * requirements for CDRW drives:
 823  * - A cache flush command must be inserted before a read request if the
 824  *   previous request was a write.
 825  * - Switching between reading and writing is slow, so don't do it more often
 826  *   than necessary.
 827  * - Optimize for throughput at the expense of latency. This means that streaming
 828  *   writes will never be interrupted by a read, but if the drive has to seek
 829  *   before the next write, switch to reading instead if there are any pending
 830  *   read requests.
 831  * - Set the read speed according to current usage pattern. When only reading
 832  *   from the device, it's best to use the highest possible read speed, but
 833  *   when switching often between reading and writing, it's better to have the
 834  *   same read and write speeds.
 835  */
 836 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
 837 {
 838
 839         if (atomic_read(&pd->iosched.attention) == 0)
 840                 return;
 841         atomic_set(&pd->iosched.attention, 0);
 842
 843         for (;;) {
 844                 struct bio *bio;
 845                 int reads_queued, writes_queued;
 846
 847                 spin_lock(&pd->iosched.lock);
 848                 reads_queued = !bio_list_empty(&pd->iosched.read_queue);
 849                 writes_queued = !bio_list_empty(&pd->iosched.write_queue);
 850                 spin_unlock(&pd->iosched.lock);
 851
 852                 if (!reads_queued && !writes_queued)
 853                         break;
 854
 855                 if (pd->iosched.writing) {
 856                         int need_write_seek = 1;
 857                         spin_lock(&pd->iosched.lock);
 858                         bio = bio_list_peek(&pd->iosched.write_queue);
 859                         spin_unlock(&pd->iosched.lock);
 860                         if (bio && (bio->bi_iter.bi_sector ==
 861                                     pd->iosched.last_write))
 862                                 need_write_seek = 0;
 863                         if (need_write_seek && reads_queued) {
 864                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 865                                         pkt_dbg(2, pd, "write, waiting\n");
 866                                         break;
 867                                 }
 868                                 pkt_flush_cache(pd);
 869                                 pd->iosched.writing = 0;
 870                         }
 871                 } else {
 872                         if (!reads_queued && writes_queued) {
 873                                 if (atomic_read(&pd->cdrw.pending_bios) > 0) {
 874                                         pkt_dbg(2, pd, "read, waiting\n");
 875                                         break;
 876                                 }
 877                                 pd->iosched.writing = 1;
 878                         }
 879                 }
 880
 881                 spin_lock(&pd->iosched.lock);
 882                 if (pd->iosched.writing)
 883                         bio = bio_list_pop(&pd->iosched.write_queue);
 884                 else
 885                         bio = bio_list_pop(&pd->iosched.read_queue);
 886                 spin_unlock(&pd->iosched.lock);
 887
 888                 if (!bio)
 889                         continue;
 890
 891                 if (bio_data_dir(bio) == READ)
 892                         pd->iosched.successive_reads +=
 893                                 bio->bi_iter.bi_size >> 10;
 894                 else {
 895                         pd->iosched.successive_reads = 0;
 896                         pd->iosched.last_write = bio_end_sector(bio);
 897                 }
 898                 if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
 899                         if (pd->read_speed == pd->write_speed) {
 900                                 pd->read_speed = MAX_SPEED;
 901                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 902                         }
 903                 } else {
 904                         if (pd->read_speed != pd->write_speed) {
 905                                 pd->read_speed = pd->write_speed;
 906                                 pkt_set_speed(pd, pd->write_speed, pd->read_speed);
 907                         }
 908                 }
 909
 910                 atomic_inc(&pd->cdrw.pending_bios);
 911                 generic_make_request(bio);
 912         }
 913 }
 914
 915 /*
 916  * Special care is needed if the underlying block device has a small
 917  * max_phys_segments value.
 918  */
 919 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
 920 {
 921         if ((pd->settings.size << 9) / CD_FRAMESIZE
 922             <= queue_max_segments(q)) {
 923                 /*
 924                  * The cdrom device can handle one segment/frame
 925                  */
 926                 clear_bit(PACKET_MERGE_SEGS, &pd->flags);
 927                 return 0;
 928         } else if ((pd->settings.size << 9) / PAGE_SIZE
 929                    <= queue_max_segments(q)) {
 930                 /*
 931                  * We can handle this case at the expense of some extra memory
 932                  * copies during write operations
 933                  */
 934                 set_bit(PACKET_MERGE_SEGS, &pd->flags);
 935                 return 0;
 936         } else {
 937                 pkt_err(pd, "cdrom max_phys_segments too small\n");
 938                 return -EIO;
 939         }
 940 }
 941
 942 /*
 943  * Copy all data for this packet to pkt->pages[], so that
 944  * a) The number of required segments for the write bio is minimized, which
 945  *    is necessary for some scsi controllers.
 946  * b) The data can be used as cache to avoid read requests if we receive a
 947  *    new write request for the same zone.
 948  */
 949 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
 950 {
 951         int f, p, offs;
 952
 953         /* Copy all data to pkt->pages[] */
 954         p = 0;
 955         offs = 0;
 956         for (f = 0; f < pkt->frames; f++) {
 957                 if (bvec[f].bv_page != pkt->pages[p]) {
 958                         void *vfrom = kmap_atomic(bvec[f].bv_page) + bvec[f].bv_offset;
 959                         void *vto = page_address(pkt->pages[p]) + offs;
 960                         memcpy(vto, vfrom, CD_FRAMESIZE);
 961                         kunmap_atomic(vfrom);
 962                         bvec[f].bv_page = pkt->pages[p];
 963                         bvec[f].bv_offset = offs;
 964                 } else {
 965                         BUG_ON(bvec[f].bv_offset != offs);
 966                 }
 967                 offs += CD_FRAMESIZE;
 968                 if (offs >= PAGE_SIZE) {
 969                         offs = 0;
 970                         p++;
 971                 }
 972         }
 973 }
 974
 975 static void pkt_end_io_read(struct bio *bio, int err)
 976 {
 977         struct packet_data *pkt = bio->bi_private;
 978         struct pktcdvd_device *pd = pkt->pd;
 979         BUG_ON(!pd);
 980
 981         pkt_dbg(2, pd, "bio=%p sec0=%llx sec=%llx err=%d\n",
 982                 bio, (unsigned long long)pkt->sector,
 983                 (unsigned long long)bio->bi_iter.bi_sector, err);
 984
 985         if (err)
 986                 atomic_inc(&pkt->io_errors);
 987         if (atomic_dec_and_test(&pkt->io_wait)) {
 988                 atomic_inc(&pkt->run_sm);
 989                 wake_up(&pd->wqueue);
 990         }
 991         pkt_bio_finished(pd);
 992 }
 993
 994 static void pkt_end_io_packet_write(struct bio *bio, int err)
 995 {
 996         struct packet_data *pkt = bio->bi_private;
 997         struct pktcdvd_device *pd = pkt->pd;
 998         BUG_ON(!pd);
 999
1000         pkt_dbg(2, pd, "id=%d, err=%d\n", pkt->id, err);
1001
1002         pd->stats.pkt_ended++;
1003
1004         pkt_bio_finished(pd);
1005         atomic_dec(&pkt->io_wait);
1006         atomic_inc(&pkt->run_sm);
1007         wake_up(&pd->wqueue);
1008 }
1009
1010 /*
1011  * Schedule reads for the holes in a packet
1012  */
1013 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1014 {
1015         int frames_read = 0;
1016         struct bio *bio;
1017         int f;
1018         char written[PACKET_MAX_SIZE];
1019
1020         BUG_ON(bio_list_empty(&pkt->orig_bios));
1021
1022         atomic_set(&pkt->io_wait, 0);
1023         atomic_set(&pkt->io_errors, 0);
1024
1025         /*
1026          * Figure out which frames we need to read before we can write.
1027          */
1028         memset(written, 0, sizeof(written));
1029         spin_lock(&pkt->lock);
1030         bio_list_for_each(bio, &pkt->orig_bios) {
1031                 int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1032                         (CD_FRAMESIZE >> 9);
1033                 int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1034                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1035                 BUG_ON(first_frame < 0);
1036                 BUG_ON(first_frame + num_frames > pkt->frames);
1037                 for (f = first_frame; f < first_frame + num_frames; f++)
1038                         written[f] = 1;
1039         }
1040         spin_unlock(&pkt->lock);
1041
1042         if (pkt->cache_valid) {
1043                 pkt_dbg(2, pd, "zone %llx cached\n",
1044                         (unsigned long long)pkt->sector);
1045                 goto out_account;
1046         }
1047
1048         /*
1049          * Schedule reads for missing parts of the packet.
1050          */
1051         for (f = 0; f < pkt->frames; f++) {
1052                 int p, offset;
1053
1054                 if (written[f])
1055                         continue;
1056
1057                 bio = pkt->r_bios[f];
1058                 bio_reset(bio);
1059                 bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1060                 bio->bi_bdev = pd->bdev;
1061                 bio->bi_end_io = pkt_end_io_read;
1062                 bio->bi_private = pkt;
1063
1064                 p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1065                 offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1066                 pkt_dbg(2, pd, "Adding frame %d, page:%p offs:%d\n",
1067                         f, pkt->pages[p], offset);
1068                 if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1069                         BUG();
1070
1071                 atomic_inc(&pkt->io_wait);
1072                 bio->bi_rw = READ;
1073                 pkt_queue_bio(pd, bio);
1074                 frames_read++;
1075         }
1076
1077 out_account:
1078         pkt_dbg(2, pd, "need %d frames for zone %llx\n",
1079                 frames_read, (unsigned long long)pkt->sector);
1080         pd->stats.pkt_started++;
1081         pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1082 }
1083
1084 /*
1085  * Find a packet matching zone, or the least recently used packet if
1086  * there is no match.
1087  */
1088 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1089 {
1090         struct packet_data *pkt;
1091
1092         list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1093                 if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1094                         list_del_init(&pkt->list);
1095                         if (pkt->sector != zone)
1096                                 pkt->cache_valid = 0;
1097                         return pkt;
1098                 }
1099         }
1100         BUG();
1101         return NULL;
1102 }
1103
1104 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1105 {
1106         if (pkt->cache_valid) {
1107                 list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1108         } else {
1109                 list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1110         }
1111 }
1112
1113 /*
1114  * recover a failed write, query for relocation if possible
1115  *
1116  * returns 1 if recovery is possible, or 0 if not
1117  *
1118  */
1119 static int pkt_start_recovery(struct packet_data *pkt)
1120 {
1121         /*
1122          * FIXME. We need help from the file system to implement
1123          * recovery handling.
1124          */
1125         return 0;
1126 #if 0
1127         struct request *rq = pkt->rq;
1128         struct pktcdvd_device *pd = rq->rq_disk->private_data;
1129         struct block_device *pkt_bdev;
1130         struct super_block *sb = NULL;
1131         unsigned long old_block, new_block;
1132         sector_t new_sector;
1133
1134         pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1135         if (pkt_bdev) {
1136                 sb = get_super(pkt_bdev);
1137                 bdput(pkt_bdev);
1138         }
1139
1140         if (!sb)
1141                 return 0;
1142
1143         if (!sb->s_op->relocate_blocks)
1144                 goto out;
1145
1146         old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1147         if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1148                 goto out;
1149
1150         new_sector = new_block * (CD_FRAMESIZE >> 9);
1151         pkt->sector = new_sector;
1152
1153         bio_reset(pkt->bio);
1154         pkt->bio->bi_bdev = pd->bdev;
1155         pkt->bio->bi_rw = REQ_WRITE;
1156         pkt->bio->bi_iter.bi_sector = new_sector;
1157         pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
1158         pkt->bio->bi_vcnt = pkt->frames;
1159
1160         pkt->bio->bi_end_io = pkt_end_io_packet_write;
1161         pkt->bio->bi_private = pkt;
1162
1163         drop_super(sb);
1164         return 1;
1165
1166 out:
1167         drop_super(sb);
1168         return 0;
1169 #endif
1170 }
1171
1172 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1173 {
1174 #if PACKET_DEBUG > 1
1175         static const char *state_name[] = {
1176                 "IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1177         };
1178         enum packet_data_state old_state = pkt->state;
1179         pkt_dbg(2, pd, "pkt %2d : s=%6llx %s -> %s\n",
1180                 pkt->id, (unsigned long long)pkt->sector,
1181                 state_name[old_state], state_name[state]);
1182 #endif
1183         pkt->state = state;
1184 }
1185
1186 /*
1187  * Scan the work queue to see if we can start a new packet.
1188  * returns non-zero if any work was done.
1189  */
1190 static int pkt_handle_queue(struct pktcdvd_device *pd)
1191 {
1192         struct packet_data *pkt, *p;
1193         struct bio *bio = NULL;
1194         sector_t zone = 0; /* Suppress gcc warning */
1195         struct pkt_rb_node *node, *first_node;
1196         struct rb_node *n;
1197         int wakeup;
1198
1199         atomic_set(&pd->scan_queue, 0);
1200
1201         if (list_empty(&pd->cdrw.pkt_free_list)) {
1202                 pkt_dbg(2, pd, "no pkt\n");
1203                 return 0;
1204         }
1205
1206         /*
1207          * Try to find a zone we are not already working on.
1208          */
1209         spin_lock(&pd->lock);
1210         first_node = pkt_rbtree_find(pd, pd->current_sector);
1211         if (!first_node) {
1212                 n = rb_first(&pd->bio_queue);
1213                 if (n)
1214                         first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1215         }
1216         node = first_node;
1217         while (node) {
1218                 bio = node->bio;
1219                 zone = get_zone(bio->bi_iter.bi_sector, pd);
1220                 list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1221                         if (p->sector == zone) {
1222                                 bio = NULL;
1223                                 goto try_next_bio;
1224                         }
1225                 }
1226                 break;
1227 try_next_bio:
1228                 node = pkt_rbtree_next(node);
1229                 if (!node) {
1230                         n = rb_first(&pd->bio_queue);
1231                         if (n)
1232                                 node = rb_entry(n, struct pkt_rb_node, rb_node);
1233                 }
1234                 if (node == first_node)
1235                         node = NULL;
1236         }
1237         spin_unlock(&pd->lock);
1238         if (!bio) {
1239                 pkt_dbg(2, pd, "no bio\n");
1240                 return 0;
1241         }
1242
1243         pkt = pkt_get_packet_data(pd, zone);
1244
1245         pd->current_sector = zone + pd->settings.size;
1246         pkt->sector = zone;
1247         BUG_ON(pkt->frames != pd->settings.size >> 2);
1248         pkt->write_size = 0;
1249
1250         /*
1251          * Scan work queue for bios in the same zone and link them
1252          * to this packet.
1253          */
1254         spin_lock(&pd->lock);
1255         pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1256         while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1257                 bio = node->bio;
1258                 pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1259                         get_zone(bio->bi_iter.bi_sector, pd));
1260                 if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1261                         break;
1262                 pkt_rbtree_erase(pd, node);
1263                 spin_lock(&pkt->lock);
1264                 bio_list_add(&pkt->orig_bios, bio);
1265                 pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1266                 spin_unlock(&pkt->lock);
1267         }
1268         /* check write congestion marks, and if bio_queue_size is
1269            below, wake up any waiters */
1270         wakeup = (pd->write_congestion_on > 0
1271                         && pd->bio_queue_size <= pd->write_congestion_off);
1272         spin_unlock(&pd->lock);
1273         if (wakeup) {
1274                 clear_bdi_congested(&pd->disk->queue->backing_dev_info,
1275                                         BLK_RW_ASYNC);
1276         }
1277
1278         pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1279         pkt_set_state(pkt, PACKET_WAITING_STATE);
1280         atomic_set(&pkt->run_sm, 1);
1281
1282         spin_lock(&pd->cdrw.active_list_lock);
1283         list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1284         spin_unlock(&pd->cdrw.active_list_lock);
1285
1286         return 1;
1287 }
1288
1289 /*
1290  * Assemble a bio to write one packet and queue the bio for processing
1291  * by the underlying block device.
1292  */
1293 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1294 {
1295         int f;
1296         struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1297
1298         bio_reset(pkt->w_bio);
1299         pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1300         pkt->w_bio->bi_bdev = pd->bdev;
1301         pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1302         pkt->w_bio->bi_private = pkt;
1303
1304         /* XXX: locking? */
1305         for (f = 0; f < pkt->frames; f++) {
1306                 bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1307                 bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1308                 if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1309                         BUG();
1310         }
1311         pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1312
1313         /*
1314          * Fill-in bvec with data from orig_bios.
1315          */
1316         spin_lock(&pkt->lock);
1317         bio_copy_data(pkt->w_bio, pkt->orig_bios.head);
1318
1319         pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1320         spin_unlock(&pkt->lock);
1321
1322         pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1323                 pkt->write_size, (unsigned long long)pkt->sector);
1324
1325         if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1326                 pkt_make_local_copy(pkt, bvec);
1327                 pkt->cache_valid = 1;
1328         } else {
1329                 pkt->cache_valid = 0;
1330         }
1331
1332         /* Start the write request */
1333         atomic_set(&pkt->io_wait, 1);
1334         pkt->w_bio->bi_rw = WRITE;
1335         pkt_queue_bio(pd, pkt->w_bio);
1336 }
1337
1338 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1339 {
1340         struct bio *bio;
1341
1342         if (!uptodate)
1343                 pkt->cache_valid = 0;
1344
1345         /* Finish all bios corresponding to this packet */
1346         while ((bio = bio_list_pop(&pkt->orig_bios)))
1347                 bio_endio(bio, uptodate ? 0 : -EIO);
1348 }
1349
1350 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1351 {
1352         int uptodate;
1353
1354         pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1355
1356         for (;;) {
1357                 switch (pkt->state) {
1358                 case PACKET_WAITING_STATE:
1359                         if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1360                                 return;
1361
1362                         pkt->sleep_time = 0;
1363                         pkt_gather_data(pd, pkt);
1364                         pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1365                         break;
1366
1367                 case PACKET_READ_WAIT_STATE:
1368                         if (atomic_read(&pkt->io_wait) > 0)
1369                                 return;
1370
1371                         if (atomic_read(&pkt->io_errors) > 0) {
1372                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1373                         } else {
1374                                 pkt_start_write(pd, pkt);
1375                         }
1376                         break;
1377
1378                 case PACKET_WRITE_WAIT_STATE:
1379                         if (atomic_read(&pkt->io_wait) > 0)
1380                                 return;
1381
1382                         if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1383                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1384                         } else {
1385                                 pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1386                         }
1387                         break;
1388
1389                 case PACKET_RECOVERY_STATE:
1390                         if (pkt_start_recovery(pkt)) {
1391                                 pkt_start_write(pd, pkt);
1392                         } else {
1393                                 pkt_dbg(2, pd, "No recovery possible\n");
1394                                 pkt_set_state(pkt, PACKET_FINISHED_STATE);
1395                         }
1396                         break;
1397
1398                 case PACKET_FINISHED_STATE:
1399                         uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1400                         pkt_finish_packet(pkt, uptodate);
1401                         return;
1402
1403                 default:
1404                         BUG();
1405                         break;
1406                 }
1407         }
1408 }
1409
1410 static void pkt_handle_packets(struct pktcdvd_device *pd)
1411 {
1412         struct packet_data *pkt, *next;
1413
1414         /*
1415          * Run state machine for active packets
1416          */
1417         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1418                 if (atomic_read(&pkt->run_sm) > 0) {
1419                         atomic_set(&pkt->run_sm, 0);
1420                         pkt_run_state_machine(pd, pkt);
1421                 }
1422         }
1423
1424         /*
1425          * Move no longer active packets to the free list
1426          */
1427         spin_lock(&pd->cdrw.active_list_lock);
1428         list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1429                 if (pkt->state == PACKET_FINISHED_STATE) {
1430                         list_del(&pkt->list);
1431                         pkt_put_packet_data(pd, pkt);
1432                         pkt_set_state(pkt, PACKET_IDLE_STATE);
1433                         atomic_set(&pd->scan_queue, 1);
1434                 }
1435         }
1436         spin_unlock(&pd->cdrw.active_list_lock);
1437 }
1438
1439 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1440 {
1441         struct packet_data *pkt;
1442         int i;
1443
1444         for (i = 0; i < PACKET_NUM_STATES; i++)
1445                 states[i] = 0;
1446
1447         spin_lock(&pd->cdrw.active_list_lock);
1448         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1449                 states[pkt->state]++;
1450         }
1451         spin_unlock(&pd->cdrw.active_list_lock);
1452 }
1453
1454 /*
1455  * kcdrwd is woken up when writes have been queued for one of our
1456  * registered devices
1457  */
1458 static int kcdrwd(void *foobar)
1459 {
1460         struct pktcdvd_device *pd = foobar;
1461         struct packet_data *pkt;
1462         long min_sleep_time, residue;
1463
1464         set_user_nice(current, -20);
1465         set_freezable();
1466
1467         for (;;) {
1468                 DECLARE_WAITQUEUE(wait, current);
1469
1470                 /*
1471                  * Wait until there is something to do
1472                  */
1473                 add_wait_queue(&pd->wqueue, &wait);
1474                 for (;;) {
1475                         set_current_state(TASK_INTERRUPTIBLE);
1476
1477                         /* Check if we need to run pkt_handle_queue */
1478                         if (atomic_read(&pd->scan_queue) > 0)
1479                                 goto work_to_do;
1480
1481                         /* Check if we need to run the state machine for some packet */
1482                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1483                                 if (atomic_read(&pkt->run_sm) > 0)
1484                                         goto work_to_do;
1485                         }
1486
1487                         /* Check if we need to process the iosched queues */
1488                         if (atomic_read(&pd->iosched.attention) != 0)
1489                                 goto work_to_do;
1490
1491                         /* Otherwise, go to sleep */
1492                         if (PACKET_DEBUG > 1) {
1493                                 int states[PACKET_NUM_STATES];
1494                                 pkt_count_states(pd, states);
1495                                 pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1496                                         states[0], states[1], states[2],
1497                                         states[3], states[4], states[5]);
1498                         }
1499
1500                         min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1501                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1502                                 if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1503                                         min_sleep_time = pkt->sleep_time;
1504                         }
1505
1506                         pkt_dbg(2, pd, "sleeping\n");
1507                         residue = schedule_timeout(min_sleep_time);
1508                         pkt_dbg(2, pd, "wake up\n");
1509
1510                         /* make swsusp happy with our thread */
1511                         try_to_freeze();
1512
1513                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1514                                 if (!pkt->sleep_time)
1515                                         continue;
1516                                 pkt->sleep_time -= min_sleep_time - residue;
1517                                 if (pkt->sleep_time <= 0) {
1518                                         pkt->sleep_time = 0;
1519                                         atomic_inc(&pkt->run_sm);
1520                                 }
1521                         }
1522
1523                         if (kthread_should_stop())
1524                                 break;
1525                 }
1526 work_to_do:
1527                 set_current_state(TASK_RUNNING);
1528                 remove_wait_queue(&pd->wqueue, &wait);
1529
1530                 if (kthread_should_stop())
1531                         break;
1532
1533                 /*
1534                  * if pkt_handle_queue returns true, we can queue
1535                  * another request.
1536                  */
1537                 while (pkt_handle_queue(pd))
1538                         ;
1539
1540                 /*
1541                  * Handle packet state machine
1542                  */
1543                 pkt_handle_packets(pd);
1544
1545                 /*
1546                  * Handle iosched queues
1547                  */
1548                 pkt_iosched_process_queue(pd);
1549         }
1550
1551         return 0;
1552 }
1553
1554 static void pkt_print_settings(struct pktcdvd_device *pd)
1555 {
1556         pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1557                  pd->settings.fp ? "Fixed" : "Variable",
1558                  pd->settings.size >> 2,
1559                  pd->settings.block_mode == 8 ? '1' : '2');
1560 }
1561
1562 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1563 {
1564         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1565
1566         cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1567         cgc->cmd[2] = page_code | (page_control << 6);
1568         cgc->cmd[7] = cgc->buflen >> 8;
1569         cgc->cmd[8] = cgc->buflen & 0xff;
1570         cgc->data_direction = CGC_DATA_READ;
1571         return pkt_generic_packet(pd, cgc);
1572 }
1573
1574 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1575 {
1576         memset(cgc->cmd, 0, sizeof(cgc->cmd));
1577         memset(cgc->buffer, 0, 2);
1578         cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1579         cgc->cmd[1] = 0x10;             /* PF */
1580         cgc->cmd[7] = cgc->buflen >> 8;
1581         cgc->cmd[8] = cgc->buflen & 0xff;
1582         cgc->data_direction = CGC_DATA_WRITE;
1583         return pkt_generic_packet(pd, cgc);
1584 }
1585
1586 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1587 {
1588         struct packet_command cgc;
1589         int ret;
1590
1591         /* set up command and get the disc info */
1592         init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1593         cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1594         cgc.cmd[8] = cgc.buflen = 2;
1595         cgc.quiet = 1;
1596
1597         if ((ret = pkt_generic_packet(pd, &cgc)))
1598                 return ret;
1599
1600         /* not all drives have the same disc_info length, so requeue
1601          * packet with the length the drive tells us it can supply
1602          */
1603         cgc.buflen = be16_to_cpu(di->disc_information_length) +
1604                      sizeof(di->disc_information_length);
1605
1606         if (cgc.buflen > sizeof(disc_information))
1607                 cgc.buflen = sizeof(disc_information);
1608
1609         cgc.cmd[8] = cgc.buflen;
1610         return pkt_generic_packet(pd, &cgc);
1611 }
1612
1613 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1614 {
1615         struct packet_command cgc;
1616         int ret;
1617
1618         init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1619         cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1620         cgc.cmd[1] = type & 3;
1621         cgc.cmd[4] = (track & 0xff00) >> 8;
1622         cgc.cmd[5] = track & 0xff;
1623         cgc.cmd[8] = 8;
1624         cgc.quiet = 1;
1625
1626         if ((ret = pkt_generic_packet(pd, &cgc)))
1627                 return ret;
1628
1629         cgc.buflen = be16_to_cpu(ti->track_information_length) +
1630                      sizeof(ti->track_information_length);
1631
1632         if (cgc.buflen > sizeof(track_information))
1633                 cgc.buflen = sizeof(track_information);
1634
1635         cgc.cmd[8] = cgc.buflen;
1636         return pkt_generic_packet(pd, &cgc);
1637 }
1638
1639 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1640                                                 long *last_written)
1641 {
1642         disc_information di;
1643         track_information ti;
1644         __u32 last_track;
1645         int ret = -1;
1646
1647         if ((ret = pkt_get_disc_info(pd, &di)))
1648                 return ret;
1649
1650         last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1651         if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1652                 return ret;
1653
1654         /* if this track is blank, try the previous. */
1655         if (ti.blank) {
1656                 last_track--;
1657                 if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1658                         return ret;
1659         }
1660
1661         /* if last recorded field is valid, return it. */
1662         if (ti.lra_v) {
1663                 *last_written = be32_to_cpu(ti.last_rec_address);
1664         } else {
1665                 /* make it up instead */
1666                 *last_written = be32_to_cpu(ti.track_start) +
1667                                 be32_to_cpu(ti.track_size);
1668                 if (ti.free_blocks)
1669                         *last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1670         }
1671         return 0;
1672 }
1673
1674 /*
1675  * write mode select package based on pd->settings
1676  */
1677 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1678 {
1679         struct packet_command cgc;
1680         struct request_sense sense;
1681         write_param_page *wp;
1682         char buffer[128];
1683         int ret, size;
1684
1685         /* doesn't apply to DVD+RW or DVD-RAM */
1686         if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1687                 return 0;
1688
1689         memset(buffer, 0, sizeof(buffer));
1690         init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1691         cgc.sense = &sense;
1692         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1693                 pkt_dump_sense(pd, &cgc);
1694                 return ret;
1695         }
1696
1697         size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1698         pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1699         if (size > sizeof(buffer))
1700                 size = sizeof(buffer);
1701
1702         /*
1703          * now get it all
1704          */
1705         init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1706         cgc.sense = &sense;
1707         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1708                 pkt_dump_sense(pd, &cgc);
1709                 return ret;
1710         }
1711
1712         /*
1713          * write page is offset header + block descriptor length
1714          */
1715         wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1716
1717         wp->fp = pd->settings.fp;
1718         wp->track_mode = pd->settings.track_mode;
1719         wp->write_type = pd->settings.write_type;
1720         wp->data_block_type = pd->settings.block_mode;
1721
1722         wp->multi_session = 0;
1723
1724 #ifdef PACKET_USE_LS
1725         wp->link_size = 7;
1726         wp->ls_v = 1;
1727 #endif
1728
1729         if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1730                 wp->session_format = 0;
1731                 wp->subhdr2 = 0x20;
1732         } else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1733                 wp->session_format = 0x20;
1734                 wp->subhdr2 = 8;
1735 #if 0
1736                 wp->mcn[0] = 0x80;
1737                 memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1738 #endif
1739         } else {
1740                 /*
1741                  * paranoia
1742                  */
1743                 pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1744                 return 1;
1745         }
1746         wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1747
1748         cgc.buflen = cgc.cmd[8] = size;
1749         if ((ret = pkt_mode_select(pd, &cgc))) {
1750                 pkt_dump_sense(pd, &cgc);
1751                 return ret;
1752         }
1753
1754         pkt_print_settings(pd);
1755         return 0;
1756 }
1757
1758 /*
1759  * 1 -- we can write to this track, 0 -- we can't
1760  */
1761 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1762 {
1763         switch (pd->mmc3_profile) {
1764                 case 0x1a: /* DVD+RW */
1765                 case 0x12: /* DVD-RAM */
1766                         /* The track is always writable on DVD+RW/DVD-RAM */
1767                         return 1;
1768                 default:
1769                         break;
1770         }
1771
1772         if (!ti->packet || !ti->fp)
1773                 return 0;
1774
1775         /*
1776          * "good" settings as per Mt Fuji.
1777          */
1778         if (ti->rt == 0 && ti->blank == 0)
1779                 return 1;
1780
1781         if (ti->rt == 0 && ti->blank == 1)
1782                 return 1;
1783
1784         if (ti->rt == 1 && ti->blank == 0)
1785                 return 1;
1786
1787         pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1788         return 0;
1789 }
1790
1791 /*
1792  * 1 -- we can write to this disc, 0 -- we can't
1793  */
1794 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1795 {
1796         switch (pd->mmc3_profile) {
1797                 case 0x0a: /* CD-RW */
1798                 case 0xffff: /* MMC3 not supported */
1799                         break;
1800                 case 0x1a: /* DVD+RW */
1801                 case 0x13: /* DVD-RW */
1802                 case 0x12: /* DVD-RAM */
1803                         return 1;
1804                 default:
1805                         pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1806                                 pd->mmc3_profile);
1807                         return 0;
1808         }
1809
1810         /*
1811          * for disc type 0xff we should probably reserve a new track.
1812          * but i'm not sure, should we leave this to user apps? probably.
1813          */
1814         if (di->disc_type == 0xff) {
1815                 pkt_notice(pd, "unknown disc - no track?\n");
1816                 return 0;
1817         }
1818
1819         if (di->disc_type != 0x20 && di->disc_type != 0) {
1820                 pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1821                 return 0;
1822         }
1823
1824         if (di->erasable == 0) {
1825                 pkt_notice(pd, "disc not erasable\n");
1826                 return 0;
1827         }
1828
1829         if (di->border_status == PACKET_SESSION_RESERVED) {
1830                 pkt_err(pd, "can't write to last track (reserved)\n");
1831                 return 0;
1832         }
1833
1834         return 1;
1835 }
1836
1837 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1838 {
1839         struct packet_command cgc;
1840         unsigned char buf[12];
1841         disc_information di;
1842         track_information ti;
1843         int ret, track;
1844
1845         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1846         cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1847         cgc.cmd[8] = 8;
1848         ret = pkt_generic_packet(pd, &cgc);
1849         pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1850
1851         memset(&di, 0, sizeof(disc_information));
1852         memset(&ti, 0, sizeof(track_information));
1853
1854         if ((ret = pkt_get_disc_info(pd, &di))) {
1855                 pkt_err(pd, "failed get_disc\n");
1856                 return ret;
1857         }
1858
1859         if (!pkt_writable_disc(pd, &di))
1860                 return -EROFS;
1861
1862         pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1863
1864         track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1865         if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1866                 pkt_err(pd, "failed get_track\n");
1867                 return ret;
1868         }
1869
1870         if (!pkt_writable_track(pd, &ti)) {
1871                 pkt_err(pd, "can't write to this track\n");
1872                 return -EROFS;
1873         }
1874
1875         /*
1876          * we keep packet size in 512 byte units, makes it easier to
1877          * deal with request calculations.
1878          */
1879         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1880         if (pd->settings.size == 0) {
1881                 pkt_notice(pd, "detected zero packet size!\n");
1882                 return -ENXIO;
1883         }
1884         if (pd->settings.size > PACKET_MAX_SECTORS) {
1885                 pkt_err(pd, "packet size is too big\n");
1886                 return -EROFS;
1887         }
1888         pd->settings.fp = ti.fp;
1889         pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1890
1891         if (ti.nwa_v) {
1892                 pd->nwa = be32_to_cpu(ti.next_writable);
1893                 set_bit(PACKET_NWA_VALID, &pd->flags);
1894         }
1895
1896         /*
1897          * in theory we could use lra on -RW media as well and just zero
1898          * blocks that haven't been written yet, but in practice that
1899          * is just a no-go. we'll use that for -R, naturally.
1900          */
1901         if (ti.lra_v) {
1902                 pd->lra = be32_to_cpu(ti.last_rec_address);
1903                 set_bit(PACKET_LRA_VALID, &pd->flags);
1904         } else {
1905                 pd->lra = 0xffffffff;
1906                 set_bit(PACKET_LRA_VALID, &pd->flags);
1907         }
1908
1909         /*
1910          * fine for now
1911          */
1912         pd->settings.link_loss = 7;
1913         pd->settings.write_type = 0;    /* packet */
1914         pd->settings.track_mode = ti.track_mode;
1915
1916         /*
1917          * mode1 or mode2 disc
1918          */
1919         switch (ti.data_mode) {
1920                 case PACKET_MODE1:
1921                         pd->settings.block_mode = PACKET_BLOCK_MODE1;
1922                         break;
1923                 case PACKET_MODE2:
1924                         pd->settings.block_mode = PACKET_BLOCK_MODE2;
1925                         break;
1926                 default:
1927                         pkt_err(pd, "unknown data mode\n");
1928                         return -EROFS;
1929         }
1930         return 0;
1931 }
1932
1933 /*
1934  * enable/disable write caching on drive
1935  */
1936 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1937                                                 int set)
1938 {
1939         struct packet_command cgc;
1940         struct request_sense sense;
1941         unsigned char buf[64];
1942         int ret;
1943
1944         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1945         cgc.sense = &sense;
1946         cgc.buflen = pd->mode_offset + 12;
1947
1948         /*
1949          * caching mode page might not be there, so quiet this command
1950          */
1951         cgc.quiet = 1;
1952
1953         if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
1954                 return ret;
1955
1956         buf[pd->mode_offset + 10] |= (!!set << 2);
1957
1958         cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1959         ret = pkt_mode_select(pd, &cgc);
1960         if (ret) {
1961                 pkt_err(pd, "write caching control failed\n");
1962                 pkt_dump_sense(pd, &cgc);
1963         } else if (!ret && set)
1964                 pkt_notice(pd, "enabled write caching\n");
1965         return ret;
1966 }
1967
1968 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1969 {
1970         struct packet_command cgc;
1971
1972         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1973         cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1974         cgc.cmd[4] = lockflag ? 1 : 0;
1975         return pkt_generic_packet(pd, &cgc);
1976 }
1977
1978 /*
1979  * Returns drive maximum write speed
1980  */
1981 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1982                                                 unsigned *write_speed)
1983 {
1984         struct packet_command cgc;
1985         struct request_sense sense;
1986         unsigned char buf[256+18];
1987         unsigned char *cap_buf;
1988         int ret, offset;
1989
1990         cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1991         init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1992         cgc.sense = &sense;
1993
1994         ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1995         if (ret) {
1996                 cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1997                              sizeof(struct mode_page_header);
1998                 ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1999                 if (ret) {
2000                         pkt_dump_sense(pd, &cgc);
2001                         return ret;
2002                 }
2003         }
2004
2005         offset = 20;                        /* Obsoleted field, used by older drives */
2006         if (cap_buf[1] >= 28)
2007                 offset = 28;                /* Current write speed selected */
2008         if (cap_buf[1] >= 30) {
2009                 /* If the drive reports at least one "Logical Unit Write
2010                  * Speed Performance Descriptor Block", use the information
2011                  * in the first block. (contains the highest speed)
2012                  */
2013                 int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2014                 if (num_spdb > 0)
2015                         offset = 34;
2016         }
2017
2018         *write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2019         return 0;
2020 }
2021
2022 /* These tables from cdrecord - I don't have orange book */
2023 /* standard speed CD-RW (1-4x) */
2024 static char clv_to_speed[16] = {
2025         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2026            0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2027 };
2028 /* high speed CD-RW (-10x) */
2029 static char hs_clv_to_speed[16] = {
2030         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2031            0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2032 };
2033 /* ultra high speed CD-RW */
2034 static char us_clv_to_speed[16] = {
2035         /* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2036            0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2037 };
2038
2039 /*
2040  * reads the maximum media speed from ATIP
2041  */
2042 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2043                                                 unsigned *speed)
2044 {
2045         struct packet_command cgc;
2046         struct request_sense sense;
2047         unsigned char buf[64];
2048         unsigned int size, st, sp;
2049         int ret;
2050
2051         init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2052         cgc.sense = &sense;
2053         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2054         cgc.cmd[1] = 2;
2055         cgc.cmd[2] = 4; /* READ ATIP */
2056         cgc.cmd[8] = 2;
2057         ret = pkt_generic_packet(pd, &cgc);
2058         if (ret) {
2059                 pkt_dump_sense(pd, &cgc);
2060                 return ret;
2061         }
2062         size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2063         if (size > sizeof(buf))
2064                 size = sizeof(buf);
2065
2066         init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2067         cgc.sense = &sense;
2068         cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2069         cgc.cmd[1] = 2;
2070         cgc.cmd[2] = 4;
2071         cgc.cmd[8] = size;
2072         ret = pkt_generic_packet(pd, &cgc);
2073         if (ret) {
2074                 pkt_dump_sense(pd, &cgc);
2075                 return ret;
2076         }
2077
2078         if (!(buf[6] & 0x40)) {
2079                 pkt_notice(pd, "disc type is not CD-RW\n");
2080                 return 1;
2081         }
2082         if (!(buf[6] & 0x4)) {
2083                 pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2084                 return 1;
2085         }
2086
2087         st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2088
2089         sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2090
2091         /* Info from cdrecord */
2092         switch (st) {
2093                 case 0: /* standard speed */
2094                         *speed = clv_to_speed[sp];
2095                         break;
2096                 case 1: /* high speed */
2097                         *speed = hs_clv_to_speed[sp];
2098                         break;
2099                 case 2: /* ultra high speed */
2100                         *speed = us_clv_to_speed[sp];
2101                         break;
2102                 default:
2103                         pkt_notice(pd, "unknown disc sub-type %d\n", st);
2104                         return 1;
2105         }
2106         if (*speed) {
2107                 pkt_info(pd, "maximum media speed: %d\n", *speed);
2108                 return 0;
2109         } else {
2110                 pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2111                 return 1;
2112         }
2113 }
2114
2115 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2116 {
2117         struct packet_command cgc;
2118         struct request_sense sense;
2119         int ret;
2120
2121         pkt_dbg(2, pd, "Performing OPC\n");
2122
2123         init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2124         cgc.sense = &sense;
2125         cgc.timeout = 60*HZ;
2126         cgc.cmd[0] = GPCMD_SEND_OPC;
2127         cgc.cmd[1] = 1;
2128         if ((ret = pkt_generic_packet(pd, &cgc)))
2129                 pkt_dump_sense(pd, &cgc);
2130         return ret;
2131 }
2132
2133 static int pkt_open_write(struct pktcdvd_device *pd)
2134 {
2135         int ret;
2136         unsigned int write_speed, media_write_speed, read_speed;
2137
2138         if ((ret = pkt_probe_settings(pd))) {
2139                 pkt_dbg(2, pd, "failed probe\n");
2140                 return ret;
2141         }
2142
2143         if ((ret = pkt_set_write_settings(pd))) {
2144                 pkt_dbg(1, pd, "failed saving write settings\n");
2145                 return -EIO;
2146         }
2147
2148         pkt_write_caching(pd, USE_WCACHING);
2149
2150         if ((ret = pkt_get_max_speed(pd, &write_speed)))
2151                 write_speed = 16 * 177;
2152         switch (pd->mmc3_profile) {
2153                 case 0x13: /* DVD-RW */
2154                 case 0x1a: /* DVD+RW */
2155                 case 0x12: /* DVD-RAM */
2156                         pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2157                         break;
2158                 default:
2159                         if ((ret = pkt_media_speed(pd, &media_write_speed)))
2160                                 media_write_speed = 16;
2161                         write_speed = min(write_speed, media_write_speed * 177);
2162                         pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2163                         break;
2164         }
2165         read_speed = write_speed;
2166
2167         if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2168                 pkt_dbg(1, pd, "couldn't set write speed\n");
2169                 return -EIO;
2170         }
2171         pd->write_speed = write_speed;
2172         pd->read_speed = read_speed;
2173
2174         if ((ret = pkt_perform_opc(pd))) {
2175                 pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2176         }
2177
2178         return 0;
2179 }
2180
2181 /*
2182  * called at open time.
2183  */
2184 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2185 {
2186         int ret;
2187         long lba;
2188         struct request_queue *q;
2189
2190         /*
2191          * We need to re-open the cdrom device without O_NONBLOCK to be able
2192          * to read/write from/to it. It is already opened in O_NONBLOCK mode
2193          * so bdget() can't fail.
2194          */
2195         bdget(pd->bdev->bd_dev);
2196         if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
2197                 goto out;
2198
2199         if ((ret = pkt_get_last_written(pd, &lba))) {
2200                 pkt_err(pd, "pkt_get_last_written failed\n");
2201                 goto out_putdev;
2202         }
2203
2204         set_capacity(pd->disk, lba << 2);
2205         set_capacity(pd->bdev->bd_disk, lba << 2);
2206         bd_set_size(pd->bdev, (loff_t)lba << 11);
2207
2208         q = bdev_get_queue(pd->bdev);
2209         if (write) {
2210                 if ((ret = pkt_open_write(pd)))
2211                         goto out_putdev;
2212                 /*
2213                  * Some CDRW drives can not handle writes larger than one packet,
2214                  * even if the size is a multiple of the packet size.
2215                  */
2216                 spin_lock_irq(q->queue_lock);
2217                 blk_queue_max_hw_sectors(q, pd->settings.size);
2218                 spin_unlock_irq(q->queue_lock);
2219                 set_bit(PACKET_WRITABLE, &pd->flags);
2220         } else {
2221                 pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2222                 clear_bit(PACKET_WRITABLE, &pd->flags);
2223         }
2224
2225         if ((ret = pkt_set_segment_merging(pd, q)))
2226                 goto out_putdev;
2227
2228         if (write) {
2229                 if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2230                         pkt_err(pd, "not enough memory for buffers\n");
2231                         ret = -ENOMEM;
2232                         goto out_putdev;
2233                 }
2234                 pkt_info(pd, "%lukB available on disc\n", lba << 1);
2235         }
2236
2237         return 0;
2238
2239 out_putdev:
2240         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2241 out:
2242         return ret;
2243 }
2244
2245 /*
2246  * called when the device is closed. makes sure that the device flushes
2247  * the internal cache before we close.
2248  */
2249 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2250 {
2251         if (flush && pkt_flush_cache(pd))
2252                 pkt_dbg(1, pd, "not flushing cache\n");
2253
2254         pkt_lock_door(pd, 0);
2255
2256         pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2257         blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2258
2259         pkt_shrink_pktlist(pd);
2260 }
2261
2262 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2263 {
2264         if (dev_minor >= MAX_WRITERS)
2265                 return NULL;
2266         return pkt_devs[dev_minor];
2267 }
2268
2269 static int pkt_open(struct block_device *bdev, fmode_t mode)
2270 {
2271         struct pktcdvd_device *pd = NULL;
2272         int ret;
2273
2274         mutex_lock(&pktcdvd_mutex);
2275         mutex_lock(&ctl_mutex);
2276         pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2277         if (!pd) {
2278                 ret = -ENODEV;
2279                 goto out;
2280         }
2281         BUG_ON(pd->refcnt < 0);
2282
2283         pd->refcnt++;
2284         if (pd->refcnt > 1) {
2285                 if ((mode & FMODE_WRITE) &&
2286                     !test_bit(PACKET_WRITABLE, &pd->flags)) {
2287                         ret = -EBUSY;
2288                         goto out_dec;
2289                 }
2290         } else {
2291                 ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2292                 if (ret)
2293                         goto out_dec;
2294                 /*
2295                  * needed here as well, since ext2 (among others) may change
2296                  * the blocksize at mount time
2297                  */
2298                 set_blocksize(bdev, CD_FRAMESIZE);
2299         }
2300
2301         mutex_unlock(&ctl_mutex);
2302         mutex_unlock(&pktcdvd_mutex);
2303         return 0;
2304
2305 out_dec:
2306         pd->refcnt--;
2307 out:
2308         mutex_unlock(&ctl_mutex);
2309         mutex_unlock(&pktcdvd_mutex);
2310         return ret;
2311 }
2312
2313 static void pkt_close(struct gendisk *disk, fmode_t mode)
2314 {
2315         struct pktcdvd_device *pd = disk->private_data;
2316
2317         mutex_lock(&pktcdvd_mutex);
2318         mutex_lock(&ctl_mutex);
2319         pd->refcnt--;
2320         BUG_ON(pd->refcnt < 0);
2321         if (pd->refcnt == 0) {
2322                 int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2323                 pkt_release_dev(pd, flush);
2324         }
2325         mutex_unlock(&ctl_mutex);
2326         mutex_unlock(&pktcdvd_mutex);
2327 }
2328
2329
2330 static void pkt_end_io_read_cloned(struct bio *bio, int err)
2331 {
2332         struct packet_stacked_data *psd = bio->bi_private;
2333         struct pktcdvd_device *pd = psd->pd;
2334
2335         bio_put(bio);
2336         bio_endio(psd->bio, err);
2337         mempool_free(psd, psd_pool);
2338         pkt_bio_finished(pd);
2339 }
2340
2341 static void pkt_make_request(struct request_queue *q, struct bio *bio)
2342 {
2343         struct pktcdvd_device *pd;
2344         char b[BDEVNAME_SIZE];
2345         sector_t zone;
2346         struct packet_data *pkt;
2347         int was_empty, blocked_bio;
2348         struct pkt_rb_node *node;
2349
2350         pd = q->queuedata;
2351         if (!pd) {
2352                 pr_err("%s incorrect request queue\n",
2353                        bdevname(bio->bi_bdev, b));
2354                 goto end_io;
2355         }
2356
2357         /*
2358          * Clone READ bios so we can have our own bi_end_io callback.
2359          */
2360         if (bio_data_dir(bio) == READ) {
2361                 struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2362                 struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2363
2364                 psd->pd = pd;
2365                 psd->bio = bio;
2366                 cloned_bio->bi_bdev = pd->bdev;
2367                 cloned_bio->bi_private = psd;
2368                 cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2369                 pd->stats.secs_r += bio_sectors(bio);
2370                 pkt_queue_bio(pd, cloned_bio);
2371                 return;
2372         }
2373
2374         if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2375                 pkt_notice(pd, "WRITE for ro device (%llu)\n",
2376                            (unsigned long long)bio->bi_iter.bi_sector);
2377                 goto end_io;
2378         }
2379
2380         if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2381                 pkt_err(pd, "wrong bio size\n");
2382                 goto end_io;
2383         }
2384
2385         blk_queue_bounce(q, &bio);
2386
2387         zone = get_zone(bio->bi_iter.bi_sector, pd);
2388         pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2389                 (unsigned long long)bio->bi_iter.bi_sector,
2390                 (unsigned long long)bio_end_sector(bio));
2391
2392         /* Check if we have to split the bio */
2393         {
2394                 struct bio_pair *bp;
2395                 sector_t last_zone;
2396                 int first_sectors;
2397
2398                 last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2399                 if (last_zone != zone) {
2400                         BUG_ON(last_zone != zone + pd->settings.size);
2401                         first_sectors = last_zone - bio->bi_iter.bi_sector;
2402                         bp = bio_split(bio, first_sectors);
2403                         BUG_ON(!bp);
2404                         pkt_make_request(q, &bp->bio1);
2405                         pkt_make_request(q, &bp->bio2);
2406                         bio_pair_release(bp);
2407                         return;
2408                 }
2409         }
2410
2411         /*
2412          * If we find a matching packet in state WAITING or READ_WAIT, we can
2413          * just append this bio to that packet.
2414          */
2415         spin_lock(&pd->cdrw.active_list_lock);
2416         blocked_bio = 0;
2417         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2418                 if (pkt->sector == zone) {
2419                         spin_lock(&pkt->lock);
2420                         if ((pkt->state == PACKET_WAITING_STATE) ||
2421                             (pkt->state == PACKET_READ_WAIT_STATE)) {
2422                                 bio_list_add(&pkt->orig_bios, bio);
2423                                 pkt->write_size +=
2424                                         bio->bi_iter.bi_size / CD_FRAMESIZE;
2425                                 if ((pkt->write_size >= pkt->frames) &&
2426                                     (pkt->state == PACKET_WAITING_STATE)) {
2427                                         atomic_inc(&pkt->run_sm);
2428                                         wake_up(&pd->wqueue);
2429                                 }
2430                                 spin_unlock(&pkt->lock);
2431                                 spin_unlock(&pd->cdrw.active_list_lock);
2432                                 return;
2433                         } else {
2434                                 blocked_bio = 1;
2435                         }
2436                         spin_unlock(&pkt->lock);
2437                 }
2438         }
2439         spin_unlock(&pd->cdrw.active_list_lock);
2440
2441         /*
2442          * Test if there is enough room left in the bio work queue
2443          * (queue size >= congestion on mark).
2444          * If not, wait till the work queue size is below the congestion off mark.
2445          */
2446         spin_lock(&pd->lock);
2447         if (pd->write_congestion_on > 0
2448             && pd->bio_queue_size >= pd->write_congestion_on) {
2449                 set_bdi_congested(&q->backing_dev_info, BLK_RW_ASYNC);
2450                 do {
2451                         spin_unlock(&pd->lock);
2452                         congestion_wait(BLK_RW_ASYNC, HZ);
2453                         spin_lock(&pd->lock);
2454                 } while(pd->bio_queue_size > pd->write_congestion_off);
2455         }
2456         spin_unlock(&pd->lock);
2457
2458         /*
2459          * No matching packet found. Store the bio in the work queue.
2460          */
2461         node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2462         node->bio = bio;
2463         spin_lock(&pd->lock);
2464         BUG_ON(pd->bio_queue_size < 0);
2465         was_empty = (pd->bio_queue_size == 0);
2466         pkt_rbtree_insert(pd, node);
2467         spin_unlock(&pd->lock);
2468
2469         /*
2470          * Wake up the worker thread.
2471          */
2472         atomic_set(&pd->scan_queue, 1);
2473         if (was_empty) {
2474                 /* This wake_up is required for correct operation */
2475                 wake_up(&pd->wqueue);
2476         } else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2477                 /*
2478                  * This wake up is not required for correct operation,
2479                  * but improves performance in some cases.
2480                  */
2481                 wake_up(&pd->wqueue);
2482         }
2483         return;
2484 end_io:
2485         bio_io_error(bio);
2486 }
2487
2488
2489
2490 static int pkt_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2491                           struct bio_vec *bvec)
2492 {
2493         struct pktcdvd_device *pd = q->queuedata;
2494         sector_t zone = get_zone(bmd->bi_sector, pd);
2495         int used = ((bmd->bi_sector - zone) << 9) + bmd->bi_size;
2496         int remaining = (pd->settings.size << 9) - used;
2497         int remaining2;
2498
2499         /*
2500          * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2501          * boundary, pkt_make_request() will split the bio.
2502          */
2503         remaining2 = PAGE_SIZE - bmd->bi_size;
2504         remaining = max(remaining, remaining2);
2505
2506         BUG_ON(remaining < 0);
2507         return remaining;
2508 }
2509
2510 static void pkt_init_queue(struct pktcdvd_device *pd)
2511 {
2512         struct request_queue *q = pd->disk->queue;
2513
2514         blk_queue_make_request(q, pkt_make_request);
2515         blk_queue_logical_block_size(q, CD_FRAMESIZE);
2516         blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2517         blk_queue_merge_bvec(q, pkt_merge_bvec);
2518         q->queuedata = pd;
2519 }
2520
2521 static int pkt_seq_show(struct seq_file *m, void *p)
2522 {
2523         struct pktcdvd_device *pd = m->private;
2524         char *msg;
2525         char bdev_buf[BDEVNAME_SIZE];
2526         int states[PACKET_NUM_STATES];
2527
2528         seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2529                    bdevname(pd->bdev, bdev_buf));
2530
2531         seq_printf(m, "\nSettings:\n");
2532         seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2533
2534         if (pd->settings.write_type == 0)
2535                 msg = "Packet";
2536         else
2537                 msg = "Unknown";
2538         seq_printf(m, "\twrite type:\t\t%s\n", msg);
2539
2540         seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2541         seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2542
2543         seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2544
2545         if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2546                 msg = "Mode 1";
2547         else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2548                 msg = "Mode 2";
2549         else
2550                 msg = "Unknown";
2551         seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2552
2553         seq_printf(m, "\nStatistics:\n");
2554         seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2555         seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2556         seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2557         seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2558         seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2559
2560         seq_printf(m, "\nMisc:\n");
2561         seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2562         seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2563         seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2564         seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2565         seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2566         seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2567
2568         seq_printf(m, "\nQueue state:\n");
2569         seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2570         seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2571         seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2572
2573         pkt_count_states(pd, states);
2574         seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2575                    states[0], states[1], states[2], states[3], states[4], states[5]);
2576
2577         seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2578                         pd->write_congestion_off,
2579                         pd->write_congestion_on);
2580         return 0;
2581 }
2582
2583 static int pkt_seq_open(struct inode *inode, struct file *file)
2584 {
2585         return single_open(file, pkt_seq_show, PDE_DATA(inode));
2586 }
2587
2588 static const struct file_operations pkt_proc_fops = {
2589         .open   = pkt_seq_open,
2590         .read   = seq_read,
2591         .llseek = seq_lseek,
2592         .release = single_release
2593 };
2594
2595 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2596 {
2597         int i;
2598         int ret = 0;
2599         char b[BDEVNAME_SIZE];
2600         struct block_device *bdev;
2601
2602         if (pd->pkt_dev == dev) {
2603                 pkt_err(pd, "recursive setup not allowed\n");
2604                 return -EBUSY;
2605         }
2606         for (i = 0; i < MAX_WRITERS; i++) {
2607                 struct pktcdvd_device *pd2 = pkt_devs[i];
2608                 if (!pd2)
2609                         continue;
2610                 if (pd2->bdev->bd_dev == dev) {
2611                         pkt_err(pd, "%s already setup\n",
2612                                 bdevname(pd2->bdev, b));
2613                         return -EBUSY;
2614                 }
2615                 if (pd2->pkt_dev == dev) {
2616                         pkt_err(pd, "can't chain pktcdvd devices\n");
2617                         return -EBUSY;
2618                 }
2619         }
2620
2621         bdev = bdget(dev);
2622         if (!bdev)
2623                 return -ENOMEM;
2624         ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
2625         if (ret)
2626                 return ret;
2627
2628         /* This is safe, since we have a reference from open(). */
2629         __module_get(THIS_MODULE);
2630
2631         pd->bdev = bdev;
2632         set_blocksize(bdev, CD_FRAMESIZE);
2633
2634         pkt_init_queue(pd);
2635
2636         atomic_set(&pd->cdrw.pending_bios, 0);
2637         pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2638         if (IS_ERR(pd->cdrw.thread)) {
2639                 pkt_err(pd, "can't start kernel thread\n");
2640                 ret = -ENOMEM;
2641                 goto out_mem;
2642         }
2643
2644         proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2645         pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2646         return 0;
2647
2648 out_mem:
2649         blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2650         /* This is safe: open() is still holding a reference. */
2651         module_put(THIS_MODULE);
2652         return ret;
2653 }
2654
2655 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2656 {
2657         struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2658         int ret;
2659
2660         pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2661                 cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2662
2663         mutex_lock(&pktcdvd_mutex);
2664         switch (cmd) {
2665         case CDROMEJECT:
2666                 /*
2667                  * The door gets locked when the device is opened, so we
2668                  * have to unlock it or else the eject command fails.
2669                  */
2670                 if (pd->refcnt == 1)
2671                         pkt_lock_door(pd, 0);
2672                 /* fallthru */
2673         /*
2674          * forward selected CDROM ioctls to CD-ROM, for UDF
2675          */
2676         case CDROMMULTISESSION:
2677         case CDROMREADTOCENTRY:
2678         case CDROM_LAST_WRITTEN:
2679         case CDROM_SEND_PACKET:
2680         case SCSI_IOCTL_SEND_COMMAND:
2681                 ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2682                 break;
2683
2684         default:
2685                 pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2686                 ret = -ENOTTY;
2687         }
2688         mutex_unlock(&pktcdvd_mutex);
2689
2690         return ret;
2691 }
2692
2693 static unsigned int pkt_check_events(struct gendisk *disk,
2694                                      unsigned int clearing)
2695 {
2696         struct pktcdvd_device *pd = disk->private_data;
2697         struct gendisk *attached_disk;
2698
2699         if (!pd)
2700                 return 0;
2701         if (!pd->bdev)
2702                 return 0;
2703         attached_disk = pd->bdev->bd_disk;
2704         if (!attached_disk || !attached_disk->fops->check_events)
2705                 return 0;
2706         return attached_disk->fops->check_events(attached_disk, clearing);
2707 }
2708
2709 static const struct block_device_operations pktcdvd_ops = {
2710         .owner =                THIS_MODULE,
2711         .open =                 pkt_open,
2712         .release =              pkt_close,
2713         .ioctl =                pkt_ioctl,
2714         .check_events =         pkt_check_events,
2715 };
2716
2717 static char *pktcdvd_devnode(struct gendisk *gd, umode_t *mode)
2718 {
2719         return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
2720 }
2721
2722 /*
2723  * Set up mapping from pktcdvd device to CD-ROM device.
2724  */
2725 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2726 {
2727         int idx;
2728         int ret = -ENOMEM;
2729         struct pktcdvd_device *pd;
2730         struct gendisk *disk;
2731
2732         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2733
2734         for (idx = 0; idx < MAX_WRITERS; idx++)
2735                 if (!pkt_devs[idx])
2736                         break;
2737         if (idx == MAX_WRITERS) {
2738                 pr_err("max %d writers supported\n", MAX_WRITERS);
2739                 ret = -EBUSY;
2740                 goto out_mutex;
2741         }
2742
2743         pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2744         if (!pd)
2745                 goto out_mutex;
2746
2747         pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2748                                                   sizeof(struct pkt_rb_node));
2749         if (!pd->rb_pool)
2750                 goto out_mem;
2751
2752         INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2753         INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2754         spin_lock_init(&pd->cdrw.active_list_lock);
2755
2756         spin_lock_init(&pd->lock);
2757         spin_lock_init(&pd->iosched.lock);
2758         bio_list_init(&pd->iosched.read_queue);
2759         bio_list_init(&pd->iosched.write_queue);
2760         sprintf(pd->name, DRIVER_NAME"%d", idx);
2761         init_waitqueue_head(&pd->wqueue);
2762         pd->bio_queue = RB_ROOT;
2763
2764         pd->write_congestion_on  = write_congestion_on;
2765         pd->write_congestion_off = write_congestion_off;
2766
2767         disk = alloc_disk(1);
2768         if (!disk)
2769                 goto out_mem;
2770         pd->disk = disk;
2771         disk->major = pktdev_major;
2772         disk->first_minor = idx;
2773         disk->fops = &pktcdvd_ops;
2774         disk->flags = GENHD_FL_REMOVABLE;
2775         strcpy(disk->disk_name, pd->name);
2776         disk->devnode = pktcdvd_devnode;
2777         disk->private_data = pd;
2778         disk->queue = blk_alloc_queue(GFP_KERNEL);
2779         if (!disk->queue)
2780                 goto out_mem2;
2781
2782         pd->pkt_dev = MKDEV(pktdev_major, idx);
2783         ret = pkt_new_dev(pd, dev);
2784         if (ret)
2785                 goto out_new_dev;
2786
2787         /* inherit events of the host device */
2788         disk->events = pd->bdev->bd_disk->events;
2789         disk->async_events = pd->bdev->bd_disk->async_events;
2790
2791         add_disk(disk);
2792
2793         pkt_sysfs_dev_new(pd);
2794         pkt_debugfs_dev_new(pd);
2795
2796         pkt_devs[idx] = pd;
2797         if (pkt_dev)
2798                 *pkt_dev = pd->pkt_dev;
2799
2800         mutex_unlock(&ctl_mutex);
2801         return 0;
2802
2803 out_new_dev:
2804         blk_cleanup_queue(disk->queue);
2805 out_mem2:
2806         put_disk(disk);
2807 out_mem:
2808         if (pd->rb_pool)
2809                 mempool_destroy(pd->rb_pool);
2810         kfree(pd);
2811 out_mutex:
2812         mutex_unlock(&ctl_mutex);
2813         pr_err("setup of pktcdvd device failed\n");
2814         return ret;
2815 }
2816
2817 /*
2818  * Tear down mapping from pktcdvd device to CD-ROM device.
2819  */
2820 static int pkt_remove_dev(dev_t pkt_dev)
2821 {
2822         struct pktcdvd_device *pd;
2823         int idx;
2824         int ret = 0;
2825
2826         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2827
2828         for (idx = 0; idx < MAX_WRITERS; idx++) {
2829                 pd = pkt_devs[idx];
2830                 if (pd && (pd->pkt_dev == pkt_dev))
2831                         break;
2832         }
2833         if (idx == MAX_WRITERS) {
2834                 pr_debug("dev not setup\n");
2835                 ret = -ENXIO;
2836                 goto out;
2837         }
2838
2839         if (pd->refcnt > 0) {
2840                 ret = -EBUSY;
2841                 goto out;
2842         }
2843         if (!IS_ERR(pd->cdrw.thread))
2844                 kthread_stop(pd->cdrw.thread);
2845
2846         pkt_devs[idx] = NULL;
2847
2848         pkt_debugfs_dev_remove(pd);
2849         pkt_sysfs_dev_remove(pd);
2850
2851         blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2852
2853         remove_proc_entry(pd->name, pkt_proc);
2854         pkt_dbg(1, pd, "writer unmapped\n");
2855
2856         del_gendisk(pd->disk);
2857         blk_cleanup_queue(pd->disk->queue);
2858         put_disk(pd->disk);
2859
2860         mempool_destroy(pd->rb_pool);
2861         kfree(pd);
2862
2863         /* This is safe: open() is still holding a reference. */
2864         module_put(THIS_MODULE);
2865
2866 out:
2867         mutex_unlock(&ctl_mutex);
2868         return ret;
2869 }
2870
2871 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2872 {
2873         struct pktcdvd_device *pd;
2874
2875         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2876
2877         pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2878         if (pd) {
2879                 ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2880                 ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2881         } else {
2882                 ctrl_cmd->dev = 0;
2883                 ctrl_cmd->pkt_dev = 0;
2884         }
2885         ctrl_cmd->num_devices = MAX_WRITERS;
2886
2887         mutex_unlock(&ctl_mutex);
2888 }
2889
2890 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2891 {
2892         void __user *argp = (void __user *)arg;
2893         struct pkt_ctrl_command ctrl_cmd;
2894         int ret = 0;
2895         dev_t pkt_dev = 0;
2896
2897         if (cmd != PACKET_CTRL_CMD)
2898                 return -ENOTTY;
2899
2900         if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2901                 return -EFAULT;
2902
2903         switch (ctrl_cmd.command) {
2904         case PKT_CTRL_CMD_SETUP:
2905                 if (!capable(CAP_SYS_ADMIN))
2906                         return -EPERM;
2907                 ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2908                 ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2909                 break;
2910         case PKT_CTRL_CMD_TEARDOWN:
2911                 if (!capable(CAP_SYS_ADMIN))
2912                         return -EPERM;
2913                 ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2914                 break;
2915         case PKT_CTRL_CMD_STATUS:
2916                 pkt_get_status(&ctrl_cmd);
2917                 break;
2918         default:
2919                 return -ENOTTY;
2920         }
2921
2922         if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2923                 return -EFAULT;
2924         return ret;
2925 }
2926
2927 #ifdef CONFIG_COMPAT
2928 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2929 {
2930         return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2931 }
2932 #endif
2933
2934 static const struct file_operations pkt_ctl_fops = {
2935         .open           = nonseekable_open,
2936         .unlocked_ioctl = pkt_ctl_ioctl,
2937 #ifdef CONFIG_COMPAT
2938         .compat_ioctl   = pkt_ctl_compat_ioctl,
2939 #endif
2940         .owner          = THIS_MODULE,
2941         .llseek         = no_llseek,
2942 };
2943
2944 static struct miscdevice pkt_misc = {
2945         .minor          = MISC_DYNAMIC_MINOR,
2946         .name           = DRIVER_NAME,
2947         .nodename       = "pktcdvd/control",
2948         .fops           = &pkt_ctl_fops
2949 };
2950
2951 static int __init pkt_init(void)
2952 {
2953         int ret;
2954
2955         mutex_init(&ctl_mutex);
2956
2957         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
2958                                         sizeof(struct packet_stacked_data));
2959         if (!psd_pool)
2960                 return -ENOMEM;
2961
2962         ret = register_blkdev(pktdev_major, DRIVER_NAME);
2963         if (ret < 0) {
2964                 pr_err("unable to register block device\n");
2965                 goto out2;
2966         }
2967         if (!pktdev_major)
2968                 pktdev_major = ret;
2969
2970         ret = pkt_sysfs_init();
2971         if (ret)
2972                 goto out;
2973
2974         pkt_debugfs_init();
2975
2976         ret = misc_register(&pkt_misc);
2977         if (ret) {
2978                 pr_err("unable to register misc device\n");
2979                 goto out_misc;
2980         }
2981
2982         pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2983
2984         return 0;
2985
2986 out_misc:
2987         pkt_debugfs_cleanup();
2988         pkt_sysfs_cleanup();
2989 out:
2990         unregister_blkdev(pktdev_major, DRIVER_NAME);
2991 out2:
2992         mempool_destroy(psd_pool);
2993         return ret;
2994 }
2995
2996 static void __exit pkt_exit(void)
2997 {
2998         remove_proc_entry("driver/"DRIVER_NAME, NULL);
2999         misc_deregister(&pkt_misc);
3000
3001         pkt_debugfs_cleanup();
3002         pkt_sysfs_cleanup();
3003
3004         unregister_blkdev(pktdev_major, DRIVER_NAME);
3005         mempool_destroy(psd_pool);
3006 }
3007
3008 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3009 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3010 MODULE_LICENSE("GPL");
3011
3012 module_init(pkt_init);
3013 module_exit(pkt_exit);