drivers/staging/hv/blkvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23 #include <linux/device.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/major.h>
  26 #include <linux/delay.h>
  27 #include <linux/hdreg.h>
  28 #include <linux/slab.h>
  29 #include <scsi/scsi.h>
  30 #include <scsi/scsi_cmnd.h>
  31 #include <scsi/scsi_eh.h>
  32 #include <scsi/scsi_dbg.h>
  33 #include "osd.h"
  34 #include "logging.h"
  35 #include "version_info.h"
  36 #include "vmbus.h"
  37 #include "storvsc_api.h"
  38
  39
  40 #define BLKVSC_MINORS   64
  41
  42 enum blkvsc_device_type {
  43         UNKNOWN_DEV_TYPE,
  44         HARDDISK_TYPE,
  45         DVD_TYPE,
  46 };
  47
  48 /*
  49  * This request ties the struct request and struct
  50  * blkvsc_request/hv_storvsc_request together A struct request may be
  51  * represented by 1 or more struct blkvsc_request
  52  */
  53 struct blkvsc_request_group {
  54         int outstanding;
  55         int status;
  56         struct list_head blkvsc_req_list;       /* list of blkvsc_requests */
  57 };
  58
  59 struct blkvsc_request {
  60         /* blkvsc_request_group.blkvsc_req_list */
  61         struct list_head req_entry;
  62
  63         /* block_device_context.pending_list */
  64         struct list_head pend_entry;
  65
  66         /* This may be null if we generate a request internally */
  67         struct request *req;
  68
  69         struct block_device_context *dev;
  70
  71         /* The group this request is part of. Maybe null */
  72         struct blkvsc_request_group *group;
  73
  74         wait_queue_head_t wevent;
  75         int cond;
  76
  77         int write;
  78         sector_t sector_start;
  79         unsigned long sector_count;
  80
  81         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];
  82         unsigned char cmd_len;
  83         unsigned char cmnd[MAX_COMMAND_SIZE];
  84
  85         struct hv_storvsc_request request;
  86         /*
  87          * !!!DO NOT ADD ANYTHING BELOW HERE!!! Otherwise, memory can overlap,
  88          * because - The extension buffer falls right here and is pointed to by
  89          * request.Extension;
  90          * Which sounds like a horrible idea, who designed this?
  91          */
  92 };
  93
  94 /* Per device structure */
  95 struct block_device_context {
  96         /* point back to our device context */
  97         struct vm_device *device_ctx;
  98         struct kmem_cache *request_pool;
  99         spinlock_t lock;
 100         struct gendisk *gd;
 101         enum blkvsc_device_type device_type;
 102         struct list_head pending_list;
 103
 104         unsigned char device_id[64];
 105         unsigned int device_id_len;
 106         int num_outstanding_reqs;
 107         int shutting_down;
 108         int media_not_present;
 109         unsigned int sector_size;
 110         sector_t capacity;
 111         unsigned int port;
 112         unsigned char path;
 113         unsigned char target;
 114         int users;
 115 };
 116
 117 /* Per driver */
 118 struct blkvsc_driver_context {
 119         /* !! These must be the first 2 fields !! */
 120         /* FIXME this is a bug! */
 121         struct driver_context drv_ctx;
 122         struct storvsc_driver_object drv_obj;
 123 };
 124
 125 /* Static decl */
 126 static int blkvsc_probe(struct device *dev);
 127 static int blkvsc_remove(struct device *device);
 128 static void blkvsc_shutdown(struct device *device);
 129
 130 static int blkvsc_open(struct block_device *bdev,  fmode_t mode);
 131 static int blkvsc_release(struct gendisk *disk, fmode_t mode);
 132 static int blkvsc_media_changed(struct gendisk *gd);
 133 static int blkvsc_revalidate_disk(struct gendisk *gd);
 134 static int blkvsc_getgeo(struct block_device *bd, struct hd_geometry *hg);
 135 static int blkvsc_ioctl(struct block_device *bd, fmode_t mode,
 136                         unsigned cmd, unsigned long argument);
 137 static void blkvsc_request(struct request_queue *queue);
 138 static void blkvsc_request_completion(struct hv_storvsc_request *request);
 139 static int blkvsc_do_request(struct block_device_context *blkdev,
 140                              struct request *req);
 141 static int blkvsc_submit_request(struct blkvsc_request *blkvsc_req,
 142                 void (*request_completion)(struct hv_storvsc_request *));
 143 static void blkvsc_init_rw(struct blkvsc_request *blkvsc_req);
 144 static void blkvsc_cmd_completion(struct hv_storvsc_request *request);
 145 static int blkvsc_do_inquiry(struct block_device_context *blkdev);
 146 static int blkvsc_do_read_capacity(struct block_device_context *blkdev);
 147 static int blkvsc_do_read_capacity16(struct block_device_context *blkdev);
 148 static int blkvsc_do_flush(struct block_device_context *blkdev);
 149 static int blkvsc_cancel_pending_reqs(struct block_device_context *blkdev);
 150 static int blkvsc_do_pending_reqs(struct block_device_context *blkdev);
 151
 152 static int blkvsc_ringbuffer_size = BLKVSC_RING_BUFFER_SIZE;
 153 module_param(blkvsc_ringbuffer_size, int, S_IRUGO);
 154 MODULE_PARM_DESC(ring_size, "Ring buffer size (in bytes)");
 155
 156 /* The one and only one */
 157 static struct blkvsc_driver_context g_blkvsc_drv;
 158
 159 static const struct block_device_operations block_ops = {
 160         .owner = THIS_MODULE,
 161         .open = blkvsc_open,
 162         .release = blkvsc_release,
 163         .media_changed = blkvsc_media_changed,
 164         .revalidate_disk = blkvsc_revalidate_disk,
 165         .getgeo = blkvsc_getgeo,
 166         .ioctl  = blkvsc_ioctl,
 167 };
 168
 169 /*
 170  * blkvsc_drv_init -  BlkVsc driver initialization.
 171  */
 172 static int blkvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 173 {
 174         struct storvsc_driver_object *storvsc_drv_obj = &g_blkvsc_drv.drv_obj;
 175         struct driver_context *drv_ctx = &g_blkvsc_drv.drv_ctx;
 176         int ret;
 177
 178         vmbus_get_interface(&storvsc_drv_obj->Base.VmbusChannelInterface);
 179
 180         storvsc_drv_obj->RingBufferSize = blkvsc_ringbuffer_size;
 181
 182         /* Callback to client driver to complete the initialization */
 183         drv_init(&storvsc_drv_obj->Base);
 184
 185         drv_ctx->driver.name = storvsc_drv_obj->Base.name;
 186         memcpy(&drv_ctx->class_id, &storvsc_drv_obj->Base.deviceType,
 187                sizeof(struct hv_guid));
 188
 189         drv_ctx->probe = blkvsc_probe;
 190         drv_ctx->remove = blkvsc_remove;
 191         drv_ctx->shutdown = blkvsc_shutdown;
 192
 193         /* The driver belongs to vmbus */
 194         ret = vmbus_child_driver_register(drv_ctx);
 195
 196         return ret;
 197 }
 198
 199 static int blkvsc_drv_exit_cb(struct device *dev, void *data)
 200 {
 201         struct device **curr = (struct device **)data;
 202         *curr = dev;
 203         return 1; /* stop iterating */
 204 }
 205
 206 static void blkvsc_drv_exit(void)
 207 {
 208         struct storvsc_driver_object *storvsc_drv_obj = &g_blkvsc_drv.drv_obj;
 209         struct driver_context *drv_ctx = &g_blkvsc_drv.drv_ctx;
 210         struct device *current_dev;
 211         int ret;
 212
 213         while (1) {
 214                 current_dev = NULL;
 215
 216                 /* Get the device */
 217                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 218                                              (void *) &current_dev,
 219                                              blkvsc_drv_exit_cb);
 220
 221                 if (ret)
 222                         DPRINT_WARN(BLKVSC_DRV,
 223                                     "driver_for_each_device returned %d", ret);
 224
 225
 226                 if (current_dev == NULL)
 227                         break;
 228
 229                 /* Initiate removal from the top-down */
 230                 device_unregister(current_dev);
 231         }
 232
 233         if (storvsc_drv_obj->Base.OnCleanup)
 234                 storvsc_drv_obj->Base.OnCleanup(&storvsc_drv_obj->Base);
 235
 236         vmbus_child_driver_unregister(drv_ctx);
 237
 238         return;
 239 }
 240
 241 /*
 242  * blkvsc_probe - Add a new device for this driver
 243  */
 244 static int blkvsc_probe(struct device *device)
 245 {
 246         struct driver_context *driver_ctx =
 247                                 driver_to_driver_context(device->driver);
 248         struct blkvsc_driver_context *blkvsc_drv_ctx =
 249                                 (struct blkvsc_driver_context *)driver_ctx;
 250         struct storvsc_driver_object *storvsc_drv_obj =
 251                                 &blkvsc_drv_ctx->drv_obj;
 252         struct vm_device *device_ctx = device_to_vm_device(device);
 253         struct hv_device *device_obj = &device_ctx->device_obj;
 254
 255         struct block_device_context *blkdev = NULL;
 256         struct storvsc_device_info device_info;
 257         int major = 0;
 258         int devnum = 0;
 259         int ret = 0;
 260         static int ide0_registered;
 261         static int ide1_registered;
 262
 263         DPRINT_DBG(BLKVSC_DRV, "blkvsc_probe - enter");
 264
 265         if (!storvsc_drv_obj->Base.OnDeviceAdd) {
 266                 DPRINT_ERR(BLKVSC_DRV, "OnDeviceAdd() not set");
 267                 ret = -1;
 268                 goto Cleanup;
 269         }
 270
 271         blkdev = kzalloc(sizeof(struct block_device_context), GFP_KERNEL);
 272         if (!blkdev) {
 273                 ret = -ENOMEM;
 274                 goto Cleanup;
 275         }
 276
 277         INIT_LIST_HEAD(&blkdev->pending_list);
 278
 279         /* Initialize what we can here */
 280         spin_lock_init(&blkdev->lock);
 281
 282         /* ASSERT(sizeof(struct blkvsc_request_group) <= */
 283         /*      sizeof(struct blkvsc_request)); */
 284
 285         blkdev->request_pool = kmem_cache_create(dev_name(&device_ctx->device),
 286                                         sizeof(struct blkvsc_request) +
 287                                         storvsc_drv_obj->RequestExtSize, 0,
 288                                         SLAB_HWCACHE_ALIGN, NULL);
 289         if (!blkdev->request_pool) {
 290                 ret = -ENOMEM;
 291                 goto Cleanup;
 292         }
 293
 294
 295         /* Call to the vsc driver to add the device */
 296         ret = storvsc_drv_obj->Base.OnDeviceAdd(device_obj, &device_info);
 297         if (ret != 0) {
 298                 DPRINT_ERR(BLKVSC_DRV, "unable to add blkvsc device");
 299                 goto Cleanup;
 300         }
 301
 302         blkdev->device_ctx = device_ctx;
 303         /* this identified the device 0 or 1 */
 304         blkdev->target = device_info.TargetId;
 305         /* this identified the ide ctrl 0 or 1 */
 306         blkdev->path = device_info.PathId;
 307
 308         dev_set_drvdata(device, blkdev);
 309
 310         /* Calculate the major and device num */
 311         if (blkdev->path == 0) {
 312                 major = IDE0_MAJOR;
 313                 devnum = blkdev->path + blkdev->target;         /* 0 or 1 */
 314
 315                 if (!ide0_registered) {
 316                         ret = register_blkdev(major, "ide");
 317                         if (ret != 0) {
 318                                 DPRINT_ERR(BLKVSC_DRV,
 319                                            "register_blkdev() failed! ret %d",
 320                                            ret);
 321                                 goto Remove;
 322                         }
 323
 324                         ide0_registered = 1;
 325                 }
 326         } else if (blkdev->path == 1) {
 327                 major = IDE1_MAJOR;
 328                 devnum = blkdev->path + blkdev->target + 1; /* 2 or 3 */
 329
 330                 if (!ide1_registered) {
 331                         ret = register_blkdev(major, "ide");
 332                         if (ret != 0) {
 333                                 DPRINT_ERR(BLKVSC_DRV,
 334                                            "register_blkdev() failed! ret %d",
 335                                            ret);
 336                                 goto Remove;
 337                         }
 338
 339                         ide1_registered = 1;
 340                 }
 341         } else {
 342                 DPRINT_ERR(BLKVSC_DRV, "invalid pathid");
 343                 ret = -1;
 344                 goto Cleanup;
 345         }
 346
 347         DPRINT_INFO(BLKVSC_DRV, "blkvsc registered for major %d!!", major);
 348
 349         blkdev->gd = alloc_disk(BLKVSC_MINORS);
 350         if (!blkdev->gd) {
 351                 DPRINT_ERR(BLKVSC_DRV, "register_blkdev() failed! ret %d", ret);
 352                 ret = -1;
 353                 goto Cleanup;
 354         }
 355
 356         blkdev->gd->queue = blk_init_queue(blkvsc_request, &blkdev->lock);
 357
 358         blk_queue_max_segment_size(blkdev->gd->queue, PAGE_SIZE);
 359         blk_queue_max_segments(blkdev->gd->queue, MAX_MULTIPAGE_BUFFER_COUNT);
 360         blk_queue_segment_boundary(blkdev->gd->queue, PAGE_SIZE-1);
 361         blk_queue_bounce_limit(blkdev->gd->queue, BLK_BOUNCE_ANY);
 362         blk_queue_dma_alignment(blkdev->gd->queue, 511);
 363
 364         blkdev->gd->major = major;
 365         if (devnum == 1 || devnum == 3)
 366                 blkdev->gd->first_minor = BLKVSC_MINORS;
 367         else
 368                 blkdev->gd->first_minor = 0;
 369         blkdev->gd->fops = &block_ops;
 370         blkdev->gd->private_data = blkdev;
 371         sprintf(blkdev->gd->disk_name, "hd%c", 'a' + devnum);
 372
 373         blkvsc_do_inquiry(blkdev);
 374         if (blkdev->device_type == DVD_TYPE) {
 375                 set_disk_ro(blkdev->gd, 1);
 376                 blkdev->gd->flags |= GENHD_FL_REMOVABLE;
 377                 blkvsc_do_read_capacity(blkdev);
 378         } else {
 379                 blkvsc_do_read_capacity16(blkdev);
 380         }
 381
 382         set_capacity(blkdev->gd, blkdev->capacity * (blkdev->sector_size/512));
 383         blk_queue_logical_block_size(blkdev->gd->queue, blkdev->sector_size);
 384         /* go! */
 385         add_disk(blkdev->gd);
 386
 387         DPRINT_INFO(BLKVSC_DRV, "%s added!! capacity %lu sector_size %d",
 388                     blkdev->gd->disk_name, (unsigned long)blkdev->capacity,
 389                     blkdev->sector_size);
 390
 391         return ret;
 392
 393 Remove:
 394         storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 395
 396 Cleanup:
 397         if (blkdev) {
 398                 if (blkdev->request_pool) {
 399                         kmem_cache_destroy(blkdev->request_pool);
 400                         blkdev->request_pool = NULL;
 401                 }
 402                 kfree(blkdev);
 403                 blkdev = NULL;
 404         }
 405
 406         return ret;
 407 }
 408
 409 static void blkvsc_shutdown(struct device *device)
 410 {
 411         struct block_device_context *blkdev = dev_get_drvdata(device);
 412         unsigned long flags;
 413
 414         if (!blkdev)
 415                 return;
 416
 417         DPRINT_DBG(BLKVSC_DRV, "blkvsc_shutdown - users %d disk %s\n",
 418                    blkdev->users, blkdev->gd->disk_name);
 419
 420         spin_lock_irqsave(&blkdev->lock, flags);
 421
 422         blkdev->shutting_down = 1;
 423
 424         blk_stop_queue(blkdev->gd->queue);
 425
 426         spin_unlock_irqrestore(&blkdev->lock, flags);
 427
 428         while (blkdev->num_outstanding_reqs) {
 429                 DPRINT_INFO(STORVSC, "waiting for %d requests to complete...",
 430                             blkdev->num_outstanding_reqs);
 431                 udelay(100);
 432         }
 433
 434         blkvsc_do_flush(blkdev);
 435
 436         spin_lock_irqsave(&blkdev->lock, flags);
 437
 438         blkvsc_cancel_pending_reqs(blkdev);
 439
 440         spin_unlock_irqrestore(&blkdev->lock, flags);
 441 }
 442
 443 static int blkvsc_do_flush(struct block_device_context *blkdev)
 444 {
 445         struct blkvsc_request *blkvsc_req;
 446
 447         DPRINT_DBG(BLKVSC_DRV, "blkvsc_do_flush()\n");
 448
 449         if (blkdev->device_type != HARDDISK_TYPE)
 450                 return 0;
 451
 452         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_KERNEL);
 453         if (!blkvsc_req)
 454                 return -ENOMEM;
 455
 456         memset(blkvsc_req, 0, sizeof(struct blkvsc_request));
 457         init_waitqueue_head(&blkvsc_req->wevent);
 458         blkvsc_req->dev = blkdev;
 459         blkvsc_req->req = NULL;
 460         blkvsc_req->write = 0;
 461
 462         blkvsc_req->request.DataBuffer.PfnArray[0] = 0;
 463         blkvsc_req->request.DataBuffer.Offset = 0;
 464         blkvsc_req->request.DataBuffer.Length = 0;
 465
 466         blkvsc_req->cmnd[0] = SYNCHRONIZE_CACHE;
 467         blkvsc_req->cmd_len = 10;
 468
 469         /*
 470          * Set this here since the completion routine may be invoked and
 471          * completed before we return
 472          */
 473         blkvsc_req->cond = 0;
 474         blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
 475
 476         wait_event_interruptible(blkvsc_req->wevent, blkvsc_req->cond);
 477
 478         kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 479
 480         return 0;
 481 }
 482
 483 /* Do a scsi INQUIRY cmd here to get the device type (ie disk or dvd) */
 484 static int blkvsc_do_inquiry(struct block_device_context *blkdev)
 485 {
 486         struct blkvsc_request *blkvsc_req;
 487         struct page *page_buf;
 488         unsigned char *buf;
 489         unsigned char device_type;
 490
 491         DPRINT_DBG(BLKVSC_DRV, "blkvsc_do_inquiry()\n");
 492
 493         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_KERNEL);
 494         if (!blkvsc_req)
 495                 return -ENOMEM;
 496
 497         memset(blkvsc_req, 0, sizeof(struct blkvsc_request));
 498         page_buf = alloc_page(GFP_KERNEL);
 499         if (!page_buf) {
 500                 kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 501                 return -ENOMEM;
 502         }
 503
 504         init_waitqueue_head(&blkvsc_req->wevent);
 505         blkvsc_req->dev = blkdev;
 506         blkvsc_req->req = NULL;
 507         blkvsc_req->write = 0;
 508
 509         blkvsc_req->request.DataBuffer.PfnArray[0] = page_to_pfn(page_buf);
 510         blkvsc_req->request.DataBuffer.Offset = 0;
 511         blkvsc_req->request.DataBuffer.Length = 64;
 512
 513         blkvsc_req->cmnd[0] = INQUIRY;
 514         blkvsc_req->cmnd[1] = 0x1;              /* Get product data */
 515         blkvsc_req->cmnd[2] = 0x83;             /* mode page 83 */
 516         blkvsc_req->cmnd[4] = 64;
 517         blkvsc_req->cmd_len = 6;
 518
 519         /*
 520          * Set this here since the completion routine may be invoked and
 521          * completed before we return
 522          */
 523         blkvsc_req->cond = 0;
 524
 525         blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
 526
 527         DPRINT_DBG(BLKVSC_DRV, "waiting %p to complete - cond %d\n",
 528                    blkvsc_req, blkvsc_req->cond);
 529
 530         wait_event_interruptible(blkvsc_req->wevent, blkvsc_req->cond);
 531
 532         buf = kmap(page_buf);
 533
 534         /* print_hex_dump_bytes("", DUMP_PREFIX_NONE, buf, 64); */
 535         /* be to le */
 536         device_type = buf[0] & 0x1F;
 537
 538         if (device_type == 0x0) {
 539                 blkdev->device_type = HARDDISK_TYPE;
 540         } else if (device_type == 0x5) {
 541                 blkdev->device_type = DVD_TYPE;
 542         } else {
 543                 /* TODO: this is currently unsupported device type */
 544                 blkdev->device_type = UNKNOWN_DEV_TYPE;
 545         }
 546
 547         DPRINT_DBG(BLKVSC_DRV, "device type %d\n", device_type);
 548
 549         blkdev->device_id_len = buf[7];
 550         if (blkdev->device_id_len > 64)
 551                 blkdev->device_id_len = 64;
 552
 553         memcpy(blkdev->device_id, &buf[8], blkdev->device_id_len);
 554         /* printk_hex_dump_bytes("", DUMP_PREFIX_NONE, blkdev->device_id,
 555          * blkdev->device_id_len); */
 556
 557         kunmap(page_buf);
 558
 559         __free_page(page_buf);
 560
 561         kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 562
 563         return 0;
 564 }
 565
 566 /* Do a scsi READ_CAPACITY cmd here to get the size of the disk */
 567 static int blkvsc_do_read_capacity(struct block_device_context *blkdev)
 568 {
 569         struct blkvsc_request *blkvsc_req;
 570         struct page *page_buf;
 571         unsigned char *buf;
 572         struct scsi_sense_hdr sense_hdr;
 573
 574         DPRINT_DBG(BLKVSC_DRV, "blkvsc_do_read_capacity()\n");
 575
 576         blkdev->sector_size = 0;
 577         blkdev->capacity = 0;
 578         blkdev->media_not_present = 0; /* assume a disk is present */
 579
 580         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_KERNEL);
 581         if (!blkvsc_req)
 582                 return -ENOMEM;
 583
 584         memset(blkvsc_req, 0, sizeof(struct blkvsc_request));
 585         page_buf = alloc_page(GFP_KERNEL);
 586         if (!page_buf) {
 587                 kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 588                 return -ENOMEM;
 589         }
 590
 591         init_waitqueue_head(&blkvsc_req->wevent);
 592         blkvsc_req->dev = blkdev;
 593         blkvsc_req->req = NULL;
 594         blkvsc_req->write = 0;
 595
 596         blkvsc_req->request.DataBuffer.PfnArray[0] = page_to_pfn(page_buf);
 597         blkvsc_req->request.DataBuffer.Offset = 0;
 598         blkvsc_req->request.DataBuffer.Length = 8;
 599
 600         blkvsc_req->cmnd[0] = READ_CAPACITY;
 601         blkvsc_req->cmd_len = 16;
 602
 603         /*
 604          * Set this here since the completion routine may be invoked
 605          * and completed before we return
 606          */
 607         blkvsc_req->cond = 0;
 608
 609         blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
 610
 611         DPRINT_DBG(BLKVSC_DRV, "waiting %p to complete - cond %d\n",
 612                    blkvsc_req, blkvsc_req->cond);
 613
 614         wait_event_interruptible(blkvsc_req->wevent, blkvsc_req->cond);
 615
 616         /* check error */
 617         if (blkvsc_req->request.Status) {
 618                 scsi_normalize_sense(blkvsc_req->sense_buffer,
 619                                      SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 620
 621                 if (sense_hdr.asc == 0x3A) {
 622                         /* Medium not present */
 623                         blkdev->media_not_present = 1;
 624                 }
 625                 return 0;
 626         }
 627         buf = kmap(page_buf);
 628
 629         /* be to le */
 630         blkdev->capacity = ((buf[0] << 24) | (buf[1] << 16) |
 631                             (buf[2] << 8) | buf[3]) + 1;
 632         blkdev->sector_size = (buf[4] << 24) | (buf[5] << 16) |
 633                               (buf[6] << 8) | buf[7];
 634
 635         kunmap(page_buf);
 636
 637         __free_page(page_buf);
 638
 639         kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 640
 641         return 0;
 642 }
 643
 644 static int blkvsc_do_read_capacity16(struct block_device_context *blkdev)
 645 {
 646         struct blkvsc_request *blkvsc_req;
 647         struct page *page_buf;
 648         unsigned char *buf;
 649         struct scsi_sense_hdr sense_hdr;
 650
 651         DPRINT_DBG(BLKVSC_DRV, "blkvsc_do_read_capacity16()\n");
 652
 653         blkdev->sector_size = 0;
 654         blkdev->capacity = 0;
 655         blkdev->media_not_present = 0; /* assume a disk is present */
 656
 657         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_KERNEL);
 658         if (!blkvsc_req)
 659                 return -ENOMEM;
 660
 661         memset(blkvsc_req, 0, sizeof(struct blkvsc_request));
 662         page_buf = alloc_page(GFP_KERNEL);
 663         if (!page_buf) {
 664                 kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 665                 return -ENOMEM;
 666         }
 667
 668         init_waitqueue_head(&blkvsc_req->wevent);
 669         blkvsc_req->dev = blkdev;
 670         blkvsc_req->req = NULL;
 671         blkvsc_req->write = 0;
 672
 673         blkvsc_req->request.DataBuffer.PfnArray[0] = page_to_pfn(page_buf);
 674         blkvsc_req->request.DataBuffer.Offset = 0;
 675         blkvsc_req->request.DataBuffer.Length = 12;
 676
 677         blkvsc_req->cmnd[0] = 0x9E; /* READ_CAPACITY16; */
 678         blkvsc_req->cmd_len = 16;
 679
 680         /*
 681          * Set this here since the completion routine may be invoked
 682          * and completed before we return
 683          */
 684         blkvsc_req->cond = 0;
 685
 686         blkvsc_submit_request(blkvsc_req, blkvsc_cmd_completion);
 687
 688         DPRINT_DBG(BLKVSC_DRV, "waiting %p to complete - cond %d\n",
 689                    blkvsc_req, blkvsc_req->cond);
 690
 691         wait_event_interruptible(blkvsc_req->wevent, blkvsc_req->cond);
 692
 693         /* check error */
 694         if (blkvsc_req->request.Status) {
 695                 scsi_normalize_sense(blkvsc_req->sense_buffer,
 696                                      SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 697                 if (sense_hdr.asc == 0x3A) {
 698                         /* Medium not present */
 699                         blkdev->media_not_present = 1;
 700                 }
 701                 return 0;
 702         }
 703         buf = kmap(page_buf);
 704
 705         /* be to le */
 706         blkdev->capacity = be64_to_cpu(*(unsigned long long *) &buf[0]) + 1;
 707         blkdev->sector_size = be32_to_cpu(*(unsigned int *)&buf[8]);
 708
 709 #if 0
 710         blkdev->capacity = ((buf[0] << 24) | (buf[1] << 16) |
 711                             (buf[2] << 8) | buf[3]) + 1;
 712         blkdev->sector_size = (buf[4] << 24) | (buf[5] << 16) |
 713                               (buf[6] << 8) | buf[7];
 714 #endif
 715
 716         kunmap(page_buf);
 717
 718         __free_page(page_buf);
 719
 720         kmem_cache_free(blkvsc_req->dev->request_pool, blkvsc_req);
 721
 722         return 0;
 723 }
 724
 725 /*
 726  * blkvsc_remove() - Callback when our device is removed
 727  */
 728 static int blkvsc_remove(struct device *device)
 729 {
 730         struct driver_context *driver_ctx =
 731                                 driver_to_driver_context(device->driver);
 732         struct blkvsc_driver_context *blkvsc_drv_ctx =
 733                                 (struct blkvsc_driver_context *)driver_ctx;
 734         struct storvsc_driver_object *storvsc_drv_obj =
 735                                 &blkvsc_drv_ctx->drv_obj;
 736         struct vm_device *device_ctx = device_to_vm_device(device);
 737         struct hv_device *device_obj = &device_ctx->device_obj;
 738         struct block_device_context *blkdev = dev_get_drvdata(device);
 739         unsigned long flags;
 740         int ret;
 741
 742         DPRINT_DBG(BLKVSC_DRV, "blkvsc_remove()\n");
 743
 744         if (!storvsc_drv_obj->Base.OnDeviceRemove)
 745                 return -1;
 746
 747         /*
 748          * Call to the vsc driver to let it know that the device is being
 749          * removed
 750          */
 751         ret = storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 752         if (ret != 0) {
 753                 /* TODO: */
 754                 DPRINT_ERR(BLKVSC_DRV,
 755                            "unable to remove blkvsc device (ret %d)", ret);
 756         }
 757
 758         /* Get to a known state */
 759         spin_lock_irqsave(&blkdev->lock, flags);
 760
 761         blkdev->shutting_down = 1;
 762
 763         blk_stop_queue(blkdev->gd->queue);
 764
 765         spin_unlock_irqrestore(&blkdev->lock, flags);
 766
 767         while (blkdev->num_outstanding_reqs) {
 768                 DPRINT_INFO(STORVSC, "waiting for %d requests to complete...",
 769                             blkdev->num_outstanding_reqs);
 770                 udelay(100);
 771         }
 772
 773         blkvsc_do_flush(blkdev);
 774
 775         spin_lock_irqsave(&blkdev->lock, flags);
 776
 777         blkvsc_cancel_pending_reqs(blkdev);
 778
 779         spin_unlock_irqrestore(&blkdev->lock, flags);
 780
 781         blk_cleanup_queue(blkdev->gd->queue);
 782
 783         del_gendisk(blkdev->gd);
 784
 785         kmem_cache_destroy(blkdev->request_pool);
 786
 787         kfree(blkdev);
 788
 789         return ret;
 790 }
 791
 792 static void blkvsc_init_rw(struct blkvsc_request *blkvsc_req)
 793 {
 794         /* ASSERT(blkvsc_req->req); */
 795         /* ASSERT(blkvsc_req->sector_count <= (MAX_MULTIPAGE_BUFFER_COUNT*8)); */
 796
 797         blkvsc_req->cmd_len = 16;
 798
 799         if (blkvsc_req->sector_start > 0xffffffff) {
 800                 if (rq_data_dir(blkvsc_req->req)) {
 801                         blkvsc_req->write = 1;
 802                         blkvsc_req->cmnd[0] = WRITE_16;
 803                 } else {
 804                         blkvsc_req->write = 0;
 805                         blkvsc_req->cmnd[0] = READ_16;
 806                 }
 807
 808                 blkvsc_req->cmnd[1] |= blk_fua_rq(blkvsc_req->req) ? 0x8 : 0;
 809
 810                 *(unsigned long long *)&blkvsc_req->cmnd[2] =
 811                                 cpu_to_be64(blkvsc_req->sector_start);
 812                 *(unsigned int *)&blkvsc_req->cmnd[10] =
 813                                 cpu_to_be32(blkvsc_req->sector_count);
 814         } else if ((blkvsc_req->sector_count > 0xff) ||
 815                    (blkvsc_req->sector_start > 0x1fffff)) {
 816                 if (rq_data_dir(blkvsc_req->req)) {
 817                         blkvsc_req->write = 1;
 818                         blkvsc_req->cmnd[0] = WRITE_10;
 819                 } else {
 820                         blkvsc_req->write = 0;
 821                         blkvsc_req->cmnd[0] = READ_10;
 822                 }
 823
 824                 blkvsc_req->cmnd[1] |= blk_fua_rq(blkvsc_req->req) ? 0x8 : 0;
 825
 826                 *(unsigned int *)&blkvsc_req->cmnd[2] =
 827                                 cpu_to_be32(blkvsc_req->sector_start);
 828                 *(unsigned short *)&blkvsc_req->cmnd[7] =
 829                                 cpu_to_be16(blkvsc_req->sector_count);
 830         } else {
 831                 if (rq_data_dir(blkvsc_req->req)) {
 832                         blkvsc_req->write = 1;
 833                         blkvsc_req->cmnd[0] = WRITE_6;
 834                 } else {
 835                         blkvsc_req->write = 0;
 836                         blkvsc_req->cmnd[0] = READ_6;
 837                 }
 838
 839                 *(unsigned int *)&blkvsc_req->cmnd[1] =
 840                                 cpu_to_be32(blkvsc_req->sector_start) >> 8;
 841                 blkvsc_req->cmnd[1] &= 0x1f;
 842                 blkvsc_req->cmnd[4] = (unsigned char)blkvsc_req->sector_count;
 843         }
 844 }
 845
 846 static int blkvsc_submit_request(struct blkvsc_request *blkvsc_req,
 847                         void (*request_completion)(struct hv_storvsc_request *))
 848 {
 849         struct block_device_context *blkdev = blkvsc_req->dev;
 850         struct vm_device *device_ctx = blkdev->device_ctx;
 851         struct driver_context *driver_ctx =
 852                         driver_to_driver_context(device_ctx->device.driver);
 853         struct blkvsc_driver_context *blkvsc_drv_ctx =
 854                         (struct blkvsc_driver_context *)driver_ctx;
 855         struct storvsc_driver_object *storvsc_drv_obj =
 856                         &blkvsc_drv_ctx->drv_obj;
 857         struct hv_storvsc_request *storvsc_req;
 858         int ret;
 859
 860         DPRINT_DBG(BLKVSC_DRV, "blkvsc_submit_request() - "
 861                    "req %p type %s start_sector %lu count %ld offset %d "
 862                    "len %d\n", blkvsc_req,
 863                    (blkvsc_req->write) ? "WRITE" : "READ",
 864                    (unsigned long) blkvsc_req->sector_start,
 865                    blkvsc_req->sector_count,
 866                    blkvsc_req->request.DataBuffer.Offset,
 867                    blkvsc_req->request.DataBuffer.Length);
 868 #if 0
 869         for (i = 0; i < (blkvsc_req->request.DataBuffer.Length >> 12); i++) {
 870                 DPRINT_DBG(BLKVSC_DRV, "blkvsc_submit_request() - "
 871                            "req %p pfn[%d] %llx\n",
 872                            blkvsc_req, i,
 873                            blkvsc_req->request.DataBuffer.PfnArray[i]);
 874         }
 875 #endif
 876
 877         storvsc_req = &blkvsc_req->request;
 878         storvsc_req->Extension = (void *)((unsigned long)blkvsc_req +
 879                                           sizeof(struct blkvsc_request));
 880
 881         storvsc_req->Type = blkvsc_req->write ? WRITE_TYPE : READ_TYPE;
 882
 883         storvsc_req->OnIOCompletion = request_completion;
 884         storvsc_req->Context = blkvsc_req;
 885
 886         storvsc_req->Host = blkdev->port;
 887         storvsc_req->Bus = blkdev->path;
 888         storvsc_req->TargetId = blkdev->target;
 889         storvsc_req->LunId = 0;  /* this is not really used at all */
 890
 891         storvsc_req->CdbLen = blkvsc_req->cmd_len;
 892         storvsc_req->Cdb = blkvsc_req->cmnd;
 893
 894         storvsc_req->SenseBuffer = blkvsc_req->sense_buffer;
 895         storvsc_req->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 896
 897         ret = storvsc_drv_obj->OnIORequest(&blkdev->device_ctx->device_obj,
 898                                            &blkvsc_req->request);
 899         if (ret == 0)
 900                 blkdev->num_outstanding_reqs++;
 901
 902         return ret;
 903 }
 904
 905 /*
 906  * We break the request into 1 or more blkvsc_requests and submit
 907  * them.  If we cant submit them all, we put them on the
 908  * pending_list. The blkvsc_request() will work on the pending_list.
 909  */
 910 static int blkvsc_do_request(struct block_device_context *blkdev,
 911                              struct request *req)
 912 {
 913         struct bio *bio = NULL;
 914         struct bio_vec *bvec = NULL;
 915         struct bio_vec *prev_bvec = NULL;
 916         struct blkvsc_request *blkvsc_req = NULL;
 917         struct blkvsc_request *tmp;
 918         int databuf_idx = 0;
 919         int seg_idx = 0;
 920         sector_t start_sector;
 921         unsigned long num_sectors = 0;
 922         int ret = 0;
 923         int pending = 0;
 924         struct blkvsc_request_group *group = NULL;
 925
 926         DPRINT_DBG(BLKVSC_DRV, "blkdev %p req %p sect %lu\n", blkdev, req,
 927                   (unsigned long)blk_rq_pos(req));
 928
 929         /* Create a group to tie req to list of blkvsc_reqs */
 930         group = kmem_cache_alloc(blkdev->request_pool, GFP_ATOMIC);
 931         if (!group)
 932                 return -ENOMEM;
 933
 934         INIT_LIST_HEAD(&group->blkvsc_req_list);
 935         group->outstanding = group->status = 0;
 936
 937         start_sector = blk_rq_pos(req);
 938
 939         /* foreach bio in the request */
 940         if (req->bio) {
 941                 for (bio = req->bio; bio; bio = bio->bi_next) {
 942                         /*
 943                          * Map this bio into an existing or new storvsc request
 944                          */
 945                         bio_for_each_segment(bvec, bio, seg_idx) {
 946                                 DPRINT_DBG(BLKVSC_DRV, "bio_for_each_segment() "
 947                                            "- req %p bio %p bvec %p seg_idx %d "
 948                                            "databuf_idx %d\n", req, bio, bvec,
 949                                            seg_idx, databuf_idx);
 950
 951                                 /* Get a new storvsc request */
 952                                 /* 1st-time */
 953                                 if ((!blkvsc_req) ||
 954                                     (databuf_idx >= MAX_MULTIPAGE_BUFFER_COUNT)
 955                                     /* hole at the begin of page */
 956                                     || (bvec->bv_offset != 0) ||
 957                                     /* hold at the end of page */
 958                                     (prev_bvec &&
 959                                      (prev_bvec->bv_len != PAGE_SIZE))) {
 960                                         /* submit the prev one */
 961                                         if (blkvsc_req) {
 962                                                 blkvsc_req->sector_start = start_sector;
 963                                                 sector_div(blkvsc_req->sector_start, (blkdev->sector_size >> 9));
 964
 965                                                 blkvsc_req->sector_count = num_sectors / (blkdev->sector_size >> 9);
 966                                                 blkvsc_init_rw(blkvsc_req);
 967                                         }
 968
 969                                         /*
 970                                          * Create new blkvsc_req to represent
 971                                          * the current bvec
 972                                          */
 973                                         blkvsc_req = kmem_cache_alloc(blkdev->request_pool, GFP_ATOMIC);
 974                                         if (!blkvsc_req) {
 975                                                 /* free up everything */
 976                                                 list_for_each_entry_safe(
 977                                                         blkvsc_req, tmp,
 978                                                         &group->blkvsc_req_list,
 979                                                         req_entry) {
 980                                                         list_del(&blkvsc_req->req_entry);
 981                                                         kmem_cache_free(blkdev->request_pool, blkvsc_req);
 982                                                 }
 983
 984                                                 kmem_cache_free(blkdev->request_pool, group);
 985                                                 return -ENOMEM;
 986                                         }
 987
 988                                         memset(blkvsc_req, 0,
 989                                                sizeof(struct blkvsc_request));
 990
 991                                         blkvsc_req->dev = blkdev;
 992                                         blkvsc_req->req = req;
 993                                         blkvsc_req->request.DataBuffer.Offset = bvec->bv_offset;
 994                                         blkvsc_req->request.DataBuffer.Length = 0;
 995
 996                                         /* Add to the group */
 997                                         blkvsc_req->group = group;
 998                                         blkvsc_req->group->outstanding++;
 999                                         list_add_tail(&blkvsc_req->req_entry,
1000                                                 &blkvsc_req->group->blkvsc_req_list);
1001
1002                                         start_sector += num_sectors;
1003                                         num_sectors = 0;
1004                                         databuf_idx = 0;
1005                                 }
1006
1007                                 /* Add the curr bvec/segment to the curr blkvsc_req */
1008                                 blkvsc_req->request.DataBuffer.PfnArray[databuf_idx] = page_to_pfn(bvec->bv_page);
1009                                 blkvsc_req->request.DataBuffer.Length += bvec->bv_len;
1010
1011                                 prev_bvec = bvec;
1012
1013                                 databuf_idx++;
1014                                 num_sectors += bvec->bv_len >> 9;
1015
1016                         } /* bio_for_each_segment */
1017
1018                 } /* rq_for_each_bio */
1019         }
1020
1021         /* Handle the last one */
1022         if (blkvsc_req) {
1023                 DPRINT_DBG(BLKVSC_DRV, "blkdev %p req %p group %p count %d\n",
1024                            blkdev, req, blkvsc_req->group,
1025                            blkvsc_req->group->outstanding);
1026
1027                 blkvsc_req->sector_start = start_sector;
1028                 sector_div(blkvsc_req->sector_start,
1029                            (blkdev->sector_size >> 9));
1030
1031                 blkvsc_req->sector_count = num_sectors /
1032                                            (blkdev->sector_size >> 9);
1033
1034                 blkvsc_init_rw(blkvsc_req);
1035         }
1036
1037         list_for_each_entry(blkvsc_req, &group->blkvsc_req_list, req_entry) {
1038                 if (pending) {
1039                         DPRINT_DBG(BLKVSC_DRV, "adding blkvsc_req to "
1040                                    "pending_list - blkvsc_req %p start_sect %lu"
1041                                    " sect_count %ld (%lu %ld)\n", blkvsc_req,
1042                                    (unsigned long)blkvsc_req->sector_start,
1043                                    blkvsc_req->sector_count,
1044                                    (unsigned long)start_sector,
1045                                    (unsigned long)num_sectors);
1046
1047                         list_add_tail(&blkvsc_req->pend_entry,
1048                                       &blkdev->pending_list);
1049                 } else {
1050                         ret = blkvsc_submit_request(blkvsc_req,
1051                                                     blkvsc_request_completion);
1052                         if (ret == -1) {
1053                                 pending = 1;
1054                                 list_add_tail(&blkvsc_req->pend_entry,
1055                                               &blkdev->pending_list);
1056                         }
1057
1058                         DPRINT_DBG(BLKVSC_DRV, "submitted blkvsc_req %p "
1059                                    "start_sect %lu sect_count %ld (%lu %ld) "
1060                                    "ret %d\n", blkvsc_req,
1061                                    (unsigned long)blkvsc_req->sector_start,
1062                                    blkvsc_req->sector_count,
1063                                    (unsigned long)start_sector,
1064                                    num_sectors, ret);
1065                 }
1066         }
1067
1068         return pending;
1069 }
1070
1071 static void blkvsc_cmd_completion(struct hv_storvsc_request *request)
1072 {
1073         struct blkvsc_request *blkvsc_req =
1074                         (struct blkvsc_request *)request->Context;
1075         struct block_device_context *blkdev =
1076                         (struct block_device_context *)blkvsc_req->dev;
1077         struct scsi_sense_hdr sense_hdr;
1078
1079         DPRINT_DBG(BLKVSC_DRV, "blkvsc_cmd_completion() - req %p\n",
1080                    blkvsc_req);
1081
1082         blkdev->num_outstanding_reqs--;
1083
1084         if (blkvsc_req->request.Status)
1085                 if (scsi_normalize_sense(blkvsc_req->sense_buffer,
1086                                          SCSI_SENSE_BUFFERSIZE, &sense_hdr))
1087                         scsi_print_sense_hdr("blkvsc", &sense_hdr);
1088
1089         blkvsc_req->cond = 1;
1090         wake_up_interruptible(&blkvsc_req->wevent);
1091 }
1092
1093 static void blkvsc_request_completion(struct hv_storvsc_request *request)
1094 {
1095         struct blkvsc_request *blkvsc_req =
1096                         (struct blkvsc_request *)request->Context;
1097         struct block_device_context *blkdev =
1098                         (struct block_device_context *)blkvsc_req->dev;
1099         unsigned long flags;
1100         struct blkvsc_request *comp_req, *tmp;
1101
1102         /* ASSERT(blkvsc_req->group); */
1103
1104         DPRINT_DBG(BLKVSC_DRV, "blkdev %p blkvsc_req %p group %p type %s "
1105                    "sect_start %lu sect_count %ld len %d group outstd %d "
1106                    "total outstd %d\n",
1107                    blkdev, blkvsc_req, blkvsc_req->group,
1108                    (blkvsc_req->write) ? "WRITE" : "READ",
1109                    (unsigned long)blkvsc_req->sector_start,
1110                    blkvsc_req->sector_count,
1111                    blkvsc_req->request.DataBuffer.Length,
1112                    blkvsc_req->group->outstanding,
1113                    blkdev->num_outstanding_reqs);
1114
1115         spin_lock_irqsave(&blkdev->lock, flags);
1116
1117         blkdev->num_outstanding_reqs--;
1118         blkvsc_req->group->outstanding--;
1119
1120         /*
1121          * Only start processing when all the blkvsc_reqs are
1122          * completed. This guarantees no out-of-order blkvsc_req
1123          * completion when calling end_that_request_first()
1124          */
1125         if (blkvsc_req->group->outstanding == 0) {
1126                 list_for_each_entry_safe(comp_req, tmp,
1127                                          &blkvsc_req->group->blkvsc_req_list,
1128                                          req_entry) {
1129                         DPRINT_DBG(BLKVSC_DRV, "completing blkvsc_req %p "
1130                                    "sect_start %lu sect_count %ld\n",
1131                                    comp_req,
1132                                    (unsigned long)comp_req->sector_start,
1133                                    comp_req->sector_count);
1134
1135                         list_del(&comp_req->req_entry);
1136
1137                         if (!__blk_end_request(comp_req->req,
1138                                 (!comp_req->request.Status ? 0 : -EIO),
1139                                 comp_req->sector_count * blkdev->sector_size)) {
1140                                 /*
1141                                  * All the sectors have been xferred ie the
1142                                  * request is done
1143                                  */
1144                                 DPRINT_DBG(BLKVSC_DRV, "req %p COMPLETED\n",
1145                                            comp_req->req);
1146                                 kmem_cache_free(blkdev->request_pool,
1147                                                 comp_req->group);
1148                         }
1149
1150                         kmem_cache_free(blkdev->request_pool, comp_req);
1151                 }
1152
1153                 if (!blkdev->shutting_down) {
1154                         blkvsc_do_pending_reqs(blkdev);
1155                         blk_start_queue(blkdev->gd->queue);
1156                         blkvsc_request(blkdev->gd->queue);
1157                 }
1158         }
1159
1160         spin_unlock_irqrestore(&blkdev->lock, flags);
1161 }
1162
1163 static int blkvsc_cancel_pending_reqs(struct block_device_context *blkdev)
1164 {
1165         struct blkvsc_request *pend_req, *tmp;
1166         struct blkvsc_request *comp_req, *tmp2;
1167
1168         int ret = 0;
1169
1170         DPRINT_DBG(BLKVSC_DRV, "blkvsc_cancel_pending_reqs()");
1171
1172         /* Flush the pending list first */
1173         list_for_each_entry_safe(pend_req, tmp, &blkdev->pending_list,
1174                                  pend_entry) {
1175                 /*
1176                  * The pend_req could be part of a partially completed
1177                  * request. If so, complete those req first until we
1178                  * hit the pend_req
1179                  */
1180                 list_for_each_entry_safe(comp_req, tmp2,
1181                                          &pend_req->group->blkvsc_req_list,
1182                                          req_entry) {
1183                         DPRINT_DBG(BLKVSC_DRV, "completing blkvsc_req %p "
1184                                    "sect_start %lu sect_count %ld\n",
1185                                    comp_req,
1186                                    (unsigned long) comp_req->sector_start,
1187                                    comp_req->sector_count);
1188
1189                         if (comp_req == pend_req)
1190                                 break;
1191
1192                         list_del(&comp_req->req_entry);
1193
1194                         if (comp_req->req) {
1195                                 ret = __blk_end_request(comp_req->req,
1196                                         (!comp_req->request.Status ? 0 : -EIO),
1197                                         comp_req->sector_count *
1198                                         blkdev->sector_size);
1199
1200                                 /* FIXME: shouldn't this do more than return? */
1201                                 if (ret)
1202                                         goto out;
1203                         }
1204
1205                         kmem_cache_free(blkdev->request_pool, comp_req);
1206                 }
1207
1208                 DPRINT_DBG(BLKVSC_DRV, "cancelling pending request - %p\n",
1209                            pend_req);
1210
1211                 list_del(&pend_req->pend_entry);
1212
1213                 list_del(&pend_req->req_entry);
1214
1215                 if (comp_req->req) {
1216                         if (!__blk_end_request(pend_req->req, -EIO,
1217                                                pend_req->sector_count *
1218                                                blkdev->sector_size)) {
1219                                 /*
1220                                  * All the sectors have been xferred ie the
1221                                  * request is done
1222                                  */
1223                                 DPRINT_DBG(BLKVSC_DRV,
1224                                            "blkvsc_cancel_pending_reqs() - "
1225                                            "req %p COMPLETED\n", pend_req->req);
1226                                 kmem_cache_free(blkdev->request_pool,
1227                                                 pend_req->group);
1228                         }
1229                 }
1230
1231                 kmem_cache_free(blkdev->request_pool, pend_req);
1232         }
1233
1234 out:
1235         return ret;
1236 }
1237
1238 static int blkvsc_do_pending_reqs(struct block_device_context *blkdev)
1239 {
1240         struct blkvsc_request *pend_req, *tmp;
1241         int ret = 0;
1242
1243         /* Flush the pending list first */
1244         list_for_each_entry_safe(pend_req, tmp, &blkdev->pending_list,
1245                                  pend_entry) {
1246                 DPRINT_DBG(BLKVSC_DRV, "working off pending_list - %p\n",
1247                            pend_req);
1248
1249                 ret = blkvsc_submit_request(pend_req,
1250                                             blkvsc_request_completion);
1251                 if (ret != 0)
1252                         break;
1253                 else
1254                         list_del(&pend_req->pend_entry);
1255         }
1256
1257         return ret;
1258 }
1259
1260 static void blkvsc_request(struct request_queue *queue)
1261 {
1262         struct block_device_context *blkdev = NULL;
1263         struct request *req;
1264         int ret = 0;
1265
1266         DPRINT_DBG(BLKVSC_DRV, "- enter\n");
1267         while ((req = blk_peek_request(queue)) != NULL) {
1268                 DPRINT_DBG(BLKVSC_DRV, "- req %p\n", req);
1269
1270                 blkdev = req->rq_disk->private_data;
1271                 if (blkdev->shutting_down || !blk_fs_request(req) ||
1272                     blkdev->media_not_present) {
1273                         __blk_end_request_cur(req, 0);
1274                         continue;
1275                 }
1276
1277                 ret = blkvsc_do_pending_reqs(blkdev);
1278
1279                 if (ret != 0) {
1280                         DPRINT_DBG(BLKVSC_DRV,
1281                                    "- stop queue - pending_list not empty\n");
1282                         blk_stop_queue(queue);
1283                         break;
1284                 }
1285
1286                 blk_start_request(req);
1287
1288                 ret = blkvsc_do_request(blkdev, req);
1289                 if (ret > 0) {
1290                         DPRINT_DBG(BLKVSC_DRV, "- stop queue - no room\n");
1291                         blk_stop_queue(queue);
1292                         break;
1293                 } else if (ret < 0) {
1294                         DPRINT_DBG(BLKVSC_DRV, "- stop queue - no mem\n");
1295                         blk_requeue_request(queue, req);
1296                         blk_stop_queue(queue);
1297                         break;
1298                 }
1299         }
1300 }
1301
1302 static int blkvsc_open(struct block_device *bdev, fmode_t mode)
1303 {
1304         struct block_device_context *blkdev = bdev->bd_disk->private_data;
1305
1306         DPRINT_DBG(BLKVSC_DRV, "- users %d disk %s\n", blkdev->users,
1307                    blkdev->gd->disk_name);
1308
1309         spin_lock(&blkdev->lock);
1310
1311         if (!blkdev->users && blkdev->device_type == DVD_TYPE) {
1312                 spin_unlock(&blkdev->lock);
1313                 check_disk_change(bdev);
1314                 spin_lock(&blkdev->lock);
1315         }
1316
1317         blkdev->users++;
1318
1319         spin_unlock(&blkdev->lock);
1320         return 0;
1321 }
1322
1323 static int blkvsc_release(struct gendisk *disk, fmode_t mode)
1324 {
1325         struct block_device_context *blkdev = disk->private_data;
1326
1327         DPRINT_DBG(BLKVSC_DRV, "- users %d disk %s\n", blkdev->users,
1328                    blkdev->gd->disk_name);
1329
1330         spin_lock(&blkdev->lock);
1331         if (blkdev->users == 1) {
1332                 spin_unlock(&blkdev->lock);
1333                 blkvsc_do_flush(blkdev);
1334                 spin_lock(&blkdev->lock);
1335         }
1336
1337         blkdev->users--;
1338
1339         spin_unlock(&blkdev->lock);
1340         return 0;
1341 }
1342
1343 static int blkvsc_media_changed(struct gendisk *gd)
1344 {
1345         DPRINT_DBG(BLKVSC_DRV, "- enter\n");
1346         return 1;
1347 }
1348
1349 static int blkvsc_revalidate_disk(struct gendisk *gd)
1350 {
1351         struct block_device_context *blkdev = gd->private_data;
1352
1353         DPRINT_DBG(BLKVSC_DRV, "- enter\n");
1354
1355         if (blkdev->device_type == DVD_TYPE) {
1356                 blkvsc_do_read_capacity(blkdev);
1357                 set_capacity(blkdev->gd, blkdev->capacity *
1358                             (blkdev->sector_size/512));
1359                 blk_queue_logical_block_size(gd->queue, blkdev->sector_size);
1360         }
1361         return 0;
1362 }
1363
1364 static int blkvsc_getgeo(struct block_device *bd, struct hd_geometry *hg)
1365 {
1366         sector_t total_sectors = get_capacity(bd->bd_disk);
1367         sector_t cylinder_times_heads = 0;
1368         sector_t temp = 0;
1369
1370         int sectors_per_track = 0;
1371         int heads = 0;
1372         int cylinders = 0;
1373         int rem = 0;
1374
1375         if (total_sectors > (65535 * 16 * 255))
1376                 total_sectors = (65535 * 16 * 255);
1377
1378         if (total_sectors >= (65535 * 16 * 63)) {
1379                 sectors_per_track = 255;
1380                 heads = 16;
1381
1382                 cylinder_times_heads = total_sectors;
1383                 /* sector_div stores the quotient in cylinder_times_heads */
1384                 rem = sector_div(cylinder_times_heads, sectors_per_track);
1385         } else {
1386                 sectors_per_track = 17;
1387
1388                 cylinder_times_heads = total_sectors;
1389                 /* sector_div stores the quotient in cylinder_times_heads */
1390                 rem = sector_div(cylinder_times_heads, sectors_per_track);
1391
1392                 temp = cylinder_times_heads + 1023;
1393                 /* sector_div stores the quotient in temp */
1394                 rem = sector_div(temp, 1024);
1395
1396                 heads = temp;
1397
1398                 if (heads < 4)
1399                         heads = 4;
1400
1401
1402                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
1403                         sectors_per_track = 31;
1404                         heads = 16;
1405
1406                         cylinder_times_heads = total_sectors;
1407                         /*
1408                          * sector_div stores the quotient in
1409                          * cylinder_times_heads
1410                          */
1411                         rem = sector_div(cylinder_times_heads,
1412                                          sectors_per_track);
1413                 }
1414
1415                 if (cylinder_times_heads >= (heads * 1024)) {
1416                         sectors_per_track = 63;
1417                         heads = 16;
1418
1419                         cylinder_times_heads = total_sectors;
1420                         /*
1421                          * sector_div stores the quotient in
1422                          * cylinder_times_heads
1423                          */
1424                         rem = sector_div(cylinder_times_heads,
1425                                          sectors_per_track);
1426                 }
1427         }
1428
1429         temp = cylinder_times_heads;
1430         /* sector_div stores the quotient in temp */
1431         rem = sector_div(temp, heads);
1432         cylinders = temp;
1433
1434         hg->heads = heads;
1435         hg->sectors = sectors_per_track;
1436         hg->cylinders = cylinders;
1437
1438         DPRINT_INFO(BLKVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
1439                     sectors_per_track);
1440
1441     return 0;
1442 }
1443
1444 static int blkvsc_ioctl(struct block_device *bd, fmode_t mode,
1445                         unsigned cmd, unsigned long argument)
1446 {
1447 /*      struct block_device_context *blkdev = bd->bd_disk->private_data; */
1448         int ret;
1449
1450         switch (cmd) {
1451         /*
1452          * TODO: I think there is certain format for HDIO_GET_IDENTITY rather
1453          * than just a GUID. Commented it out for now.
1454          */
1455 #if 0
1456         case HDIO_GET_IDENTITY:
1457                 DPRINT_INFO(BLKVSC_DRV, "HDIO_GET_IDENTITY\n");
1458                 if (copy_to_user((void __user *)arg, blkdev->device_id,
1459                                  blkdev->device_id_len))
1460                         ret = -EFAULT;
1461                 break;
1462 #endif
1463         default:
1464                 ret = -EINVAL;
1465                 break;
1466         }
1467
1468         return ret;
1469 }
1470
1471 static int __init blkvsc_init(void)
1472 {
1473         int ret;
1474
1475         BUILD_BUG_ON(sizeof(sector_t) != 8);
1476
1477         DPRINT_INFO(BLKVSC_DRV, "Blkvsc initializing....");
1478
1479         ret = blkvsc_drv_init(BlkVscInitialize);
1480
1481         return ret;
1482 }
1483
1484 static void __exit blkvsc_exit(void)
1485 {
1486         blkvsc_drv_exit();
1487 }
1488
1489 MODULE_LICENSE("GPL");
1490 MODULE_VERSION(HV_DRV_VERSION);
1491 MODULE_DESCRIPTION("Microsoft Hyper-V virtual block driver");
1492 module_init(blkvsc_init);
1493 module_exit(blkvsc_exit);