drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
  11  *
  12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  */
  20
  21 static int sg_version_num = 30534;      /* 2 digits for each component */
  22 #define SG_VERSION_STR "3.5.34"
  23
  24 /*
  25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  28  *        (otherwise the macros compile to empty statements).
  29  *
  30  */
  31 #include <linux/module.h>
  32
  33 #include <linux/fs.h>
  34 #include <linux/kernel.h>
  35 #include <linux/sched.h>
  36 #include <linux/string.h>
  37 #include <linux/mm.h>
  38 #include <linux/errno.h>
  39 #include <linux/mtio.h>
  40 #include <linux/ioctl.h>
  41 #include <linux/fcntl.h>
  42 #include <linux/init.h>
  43 #include <linux/poll.h>
  44 #include <linux/moduleparam.h>
  45 #include <linux/cdev.h>
  46 #include <linux/idr.h>
  47 #include <linux/seq_file.h>
  48 #include <linux/blkdev.h>
  49 #include <linux/delay.h>
  50 #include <linux/blktrace_api.h>
  51 #include <linux/smp_lock.h>
  52
  53 #include "scsi.h"
  54 #include <scsi/scsi_dbg.h>
  55 #include <scsi/scsi_host.h>
  56 #include <scsi/scsi_driver.h>
  57 #include <scsi/scsi_ioctl.h>
  58 #include <scsi/sg.h>
  59
  60 #include "scsi_logging.h"
  61
  62 #ifdef CONFIG_SCSI_PROC_FS
  63 #include <linux/proc_fs.h>
  64 static char *sg_version_date = "20061027";
  65
  66 static int sg_proc_init(void);
  67 static void sg_proc_cleanup(void);
  68 #endif
  69
  70 #define SG_ALLOW_DIO_DEF 0
  71
  72 #define SG_MAX_DEVS 32768
  73
  74 /*
  75  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  76  * Then when using 32 bit integers x * m may overflow during the calculation.
  77  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  78  * calculates the same, but prevents the overflow when both m and d
  79  * are "small" numbers (like HZ and USER_HZ).
  80  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  81  * in 32 bits.
  82  */
  83 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  84
  85 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  86
  87 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  88 /* N.B. This variable is readable and writeable via
  89    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  90    of this size (or less if there is not enough memory) will be reserved
  91    for use by this file descriptor. [Deprecated usage: this variable is also
  92    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  93    the kernel (i.e. it is not a module).] */
  94 static int def_reserved_size = -1;      /* picks up init parameter */
  95 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  96
  97 static int scatter_elem_sz = SG_SCATTER_SZ;
  98 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  99
 100 #define SG_SECTOR_SZ 512
 101 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 102
 103 static int sg_add(struct device *, struct class_interface *);
 104 static void sg_remove(struct device *, struct class_interface *);
 105
 106 static DEFINE_IDR(sg_index_idr);
 107 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 108                                                            file descriptor list for device */
 109
 110 static struct class_interface sg_interface = {
 111         .add_dev        = sg_add,
 112         .remove_dev     = sg_remove,
 113 };
 114
 115 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 116         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 117         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 118         unsigned bufflen;       /* Size of (aggregate) data buffer */
 119         struct page **pages;
 120         int page_order;
 121         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 122         unsigned char cmd_opcode; /* first byte of command */
 123 } Sg_scatter_hold;
 124
 125 struct sg_device;               /* forward declarations */
 126 struct sg_fd;
 127
 128 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 129         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 130         struct sg_fd *parentfp; /* NULL -> not in use */
 131         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 132         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 133         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 134         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 135         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 136         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 137         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 138         struct request *rq;
 139         struct bio *bio;
 140 } Sg_request;
 141
 142 typedef struct sg_fd {          /* holds the state of a file descriptor */
 143         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 144         struct sg_device *parentdp;     /* owning device */
 145         wait_queue_head_t read_wait;    /* queue read until command done */
 146         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 147         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 148         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 149         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 150         unsigned save_scat_len; /* original length of trunc. scat. element */
 151         Sg_request *headrp;     /* head of request slist, NULL->empty */
 152         struct fasync_struct *async_qp; /* used by asynchronous notification */
 153         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 154         char low_dma;           /* as in parent but possibly overridden to 1 */
 155         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 156         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 157         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 158         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 159         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 160         char mmap_called;       /* 0 -> mmap() never called on this fd */
 161 } Sg_fd;
 162
 163 typedef struct sg_device { /* holds the state of each scsi generic device */
 164         struct scsi_device *device;
 165         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 166         int sg_tablesize;       /* adapter's max scatter-gather table size */
 167         u32 index;              /* device index number */
 168         Sg_fd *headfp;          /* first open fd belonging to this device */
 169         volatile char detached; /* 0->attached, 1->detached pending removal */
 170         volatile char exclude;  /* opened for exclusive access */
 171         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 172         struct gendisk *disk;
 173         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 174 } Sg_device;
 175
 176 static int sg_fasync(int fd, struct file *filp, int mode);
 177 /* tasklet or soft irq callback */
 178 static void sg_rq_end_io(struct request *rq, int uptodate);
 179 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 180 static void sg_finish_rem_req(Sg_request * srp);
 181 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 182 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
 183                          int tablesize);
 184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185                            Sg_request * srp);
 186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187                         const char __user *buf, size_t count, int blocking,
 188                         int read_only, Sg_request **o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 192 static void sg_remove_scat(Sg_scatter_hold * schp);
 193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 196 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 197 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 198 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 199 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 200 static Sg_request *sg_add_request(Sg_fd * sfp);
 201 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 202 static int sg_res_in_use(Sg_fd * sfp);
 203 static Sg_device *sg_get_dev(int dev);
 204 #ifdef CONFIG_SCSI_PROC_FS
 205 static int sg_last_dev(void);
 206 #endif
 207
 208 #define SZ_SG_HEADER sizeof(struct sg_header)
 209 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 210 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 211 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 212
 213 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 214 {
 215         struct sg_fd *sfp = (struct sg_fd *)filp->private_data;
 216         struct request_queue *q = sfp->parentdp->device->request_queue;
 217
 218         if (sfp->parentdp->device->type == TYPE_SCANNER)
 219                 return 0;
 220
 221         return blk_verify_command(&q->cmd_filter,
 222                                   cmd, filp->f_mode & FMODE_WRITE);
 223 }
 224
 225 static int
 226 sg_open(struct inode *inode, struct file *filp)
 227 {
 228         int dev = iminor(inode);
 229         int flags = filp->f_flags;
 230         struct request_queue *q;
 231         Sg_device *sdp;
 232         Sg_fd *sfp;
 233         int res;
 234         int retval;
 235
 236         lock_kernel();
 237         nonseekable_open(inode, filp);
 238         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 239         sdp = sg_get_dev(dev);
 240         if ((!sdp) || (!sdp->device)) {
 241                 unlock_kernel();
 242                 return -ENXIO;
 243         }
 244         if (sdp->detached) {
 245                 unlock_kernel();
 246                 return -ENODEV;
 247         }
 248
 249         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 250         /* Prevent the device driver from vanishing while we sleep */
 251         retval = scsi_device_get(sdp->device);
 252         if (retval) {
 253                 unlock_kernel();
 254                 return retval;
 255         }
 256
 257         if (!((flags & O_NONBLOCK) ||
 258               scsi_block_when_processing_errors(sdp->device))) {
 259                 retval = -ENXIO;
 260                 /* we are in error recovery for this device */
 261                 goto error_out;
 262         }
 263
 264         if (flags & O_EXCL) {
 265                 if (O_RDONLY == (flags & O_ACCMODE)) {
 266                         retval = -EPERM; /* Can't lock it with read only access */
 267                         goto error_out;
 268                 }
 269                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 270                         retval = -EBUSY;
 271                         goto error_out;
 272                 }
 273                 res = 0;
 274                 __wait_event_interruptible(sdp->o_excl_wait,
 275                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 276                 if (res) {
 277                         retval = res;   /* -ERESTARTSYS because signal hit process */
 278                         goto error_out;
 279                 }
 280         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 281                 if (flags & O_NONBLOCK) {
 282                         retval = -EBUSY;
 283                         goto error_out;
 284                 }
 285                 res = 0;
 286                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 287                                            res);
 288                 if (res) {
 289                         retval = res;   /* -ERESTARTSYS because signal hit process */
 290                         goto error_out;
 291                 }
 292         }
 293         if (sdp->detached) {
 294                 retval = -ENODEV;
 295                 goto error_out;
 296         }
 297         if (!sdp->headfp) {     /* no existing opens on this device */
 298                 sdp->sgdebug = 0;
 299                 q = sdp->device->request_queue;
 300                 sdp->sg_tablesize = min(q->max_hw_segments,
 301                                         q->max_phys_segments);
 302         }
 303         if ((sfp = sg_add_sfp(sdp, dev)))
 304                 filp->private_data = sfp;
 305         else {
 306                 if (flags & O_EXCL)
 307                         sdp->exclude = 0;       /* undo if error */
 308                 retval = -ENOMEM;
 309                 goto error_out;
 310         }
 311         unlock_kernel();
 312         return 0;
 313
 314       error_out:
 315         scsi_device_put(sdp->device);
 316         unlock_kernel();
 317         return retval;
 318 }
 319
 320 /* Following function was formerly called 'sg_close' */
 321 static int
 322 sg_release(struct inode *inode, struct file *filp)
 323 {
 324         Sg_device *sdp;
 325         Sg_fd *sfp;
 326
 327         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 328                 return -ENXIO;
 329         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 330         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 331         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 332                 if (!sdp->detached) {
 333                         scsi_device_put(sdp->device);
 334                 }
 335                 sdp->exclude = 0;
 336                 wake_up_interruptible(&sdp->o_excl_wait);
 337         }
 338         return 0;
 339 }
 340
 341 static ssize_t
 342 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 343 {
 344         Sg_device *sdp;
 345         Sg_fd *sfp;
 346         Sg_request *srp;
 347         int req_pack_id = -1;
 348         sg_io_hdr_t *hp;
 349         struct sg_header *old_hdr = NULL;
 350         int retval = 0;
 351
 352         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 353                 return -ENXIO;
 354         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 355                                    sdp->disk->disk_name, (int) count));
 356
 357         if (!access_ok(VERIFY_WRITE, buf, count))
 358                 return -EFAULT;
 359         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 360                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 361                 if (!old_hdr)
 362                         return -ENOMEM;
 363                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 364                         retval = -EFAULT;
 365                         goto free_old_hdr;
 366                 }
 367                 if (old_hdr->reply_len < 0) {
 368                         if (count >= SZ_SG_IO_HDR) {
 369                                 sg_io_hdr_t *new_hdr;
 370                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 371                                 if (!new_hdr) {
 372                                         retval = -ENOMEM;
 373                                         goto free_old_hdr;
 374                                 }
 375                                 retval =__copy_from_user
 376                                     (new_hdr, buf, SZ_SG_IO_HDR);
 377                                 req_pack_id = new_hdr->pack_id;
 378                                 kfree(new_hdr);
 379                                 if (retval) {
 380                                         retval = -EFAULT;
 381                                         goto free_old_hdr;
 382                                 }
 383                         }
 384                 } else
 385                         req_pack_id = old_hdr->pack_id;
 386         }
 387         srp = sg_get_rq_mark(sfp, req_pack_id);
 388         if (!srp) {             /* now wait on packet to arrive */
 389                 if (sdp->detached) {
 390                         retval = -ENODEV;
 391                         goto free_old_hdr;
 392                 }
 393                 if (filp->f_flags & O_NONBLOCK) {
 394                         retval = -EAGAIN;
 395                         goto free_old_hdr;
 396                 }
 397                 while (1) {
 398                         retval = 0; /* following macro beats race condition */
 399                         __wait_event_interruptible(sfp->read_wait,
 400                                 (sdp->detached ||
 401                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 402                                 retval);
 403                         if (sdp->detached) {
 404                                 retval = -ENODEV;
 405                                 goto free_old_hdr;
 406                         }
 407                         if (0 == retval)
 408                                 break;
 409
 410                         /* -ERESTARTSYS as signal hit process */
 411                         goto free_old_hdr;
 412                 }
 413         }
 414         if (srp->header.interface_id != '\0') {
 415                 retval = sg_new_read(sfp, buf, count, srp);
 416                 goto free_old_hdr;
 417         }
 418
 419         hp = &srp->header;
 420         if (old_hdr == NULL) {
 421                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 422                 if (! old_hdr) {
 423                         retval = -ENOMEM;
 424                         goto free_old_hdr;
 425                 }
 426         }
 427         memset(old_hdr, 0, SZ_SG_HEADER);
 428         old_hdr->reply_len = (int) hp->timeout;
 429         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 430         old_hdr->pack_id = hp->pack_id;
 431         old_hdr->twelve_byte =
 432             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 433         old_hdr->target_status = hp->masked_status;
 434         old_hdr->host_status = hp->host_status;
 435         old_hdr->driver_status = hp->driver_status;
 436         if ((CHECK_CONDITION & hp->masked_status) ||
 437             (DRIVER_SENSE & hp->driver_status))
 438                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 439                        sizeof (old_hdr->sense_buffer));
 440         switch (hp->host_status) {
 441         /* This setup of 'result' is for backward compatibility and is best
 442            ignored by the user who should use target, host + driver status */
 443         case DID_OK:
 444         case DID_PASSTHROUGH:
 445         case DID_SOFT_ERROR:
 446                 old_hdr->result = 0;
 447                 break;
 448         case DID_NO_CONNECT:
 449         case DID_BUS_BUSY:
 450         case DID_TIME_OUT:
 451                 old_hdr->result = EBUSY;
 452                 break;
 453         case DID_BAD_TARGET:
 454         case DID_ABORT:
 455         case DID_PARITY:
 456         case DID_RESET:
 457         case DID_BAD_INTR:
 458                 old_hdr->result = EIO;
 459                 break;
 460         case DID_ERROR:
 461                 old_hdr->result = (srp->sense_b[0] == 0 &&
 462                                   hp->masked_status == GOOD) ? 0 : EIO;
 463                 break;
 464         default:
 465                 old_hdr->result = EIO;
 466                 break;
 467         }
 468
 469         /* Now copy the result back to the user buffer.  */
 470         if (count >= SZ_SG_HEADER) {
 471                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 472                         retval = -EFAULT;
 473                         goto free_old_hdr;
 474                 }
 475                 buf += SZ_SG_HEADER;
 476                 if (count > old_hdr->reply_len)
 477                         count = old_hdr->reply_len;
 478                 if (count > SZ_SG_HEADER) {
 479                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 480                                 retval = -EFAULT;
 481                                 goto free_old_hdr;
 482                         }
 483                 }
 484         } else
 485                 count = (old_hdr->result == 0) ? 0 : -EIO;
 486         sg_finish_rem_req(srp);
 487         retval = count;
 488 free_old_hdr:
 489         kfree(old_hdr);
 490         return retval;
 491 }
 492
 493 static ssize_t
 494 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 495 {
 496         sg_io_hdr_t *hp = &srp->header;
 497         int err = 0;
 498         int len;
 499
 500         if (count < SZ_SG_IO_HDR) {
 501                 err = -EINVAL;
 502                 goto err_out;
 503         }
 504         hp->sb_len_wr = 0;
 505         if ((hp->mx_sb_len > 0) && hp->sbp) {
 506                 if ((CHECK_CONDITION & hp->masked_status) ||
 507                     (DRIVER_SENSE & hp->driver_status)) {
 508                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 509                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 510                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 511                         len = (len > sb_len) ? sb_len : len;
 512                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 513                                 err = -EFAULT;
 514                                 goto err_out;
 515                         }
 516                         hp->sb_len_wr = len;
 517                 }
 518         }
 519         if (hp->masked_status || hp->host_status || hp->driver_status)
 520                 hp->info |= SG_INFO_CHECK;
 521         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 522                 err = -EFAULT;
 523                 goto err_out;
 524         }
 525         if (srp->bio) {
 526                 err = blk_rq_unmap_user(srp->bio);
 527                 srp->bio = NULL;
 528         }
 529 err_out:
 530         sg_finish_rem_req(srp);
 531         return (0 == err) ? count : err;
 532 }
 533
 534 static ssize_t
 535 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 536 {
 537         int mxsize, cmd_size, k;
 538         int input_size, blocking;
 539         unsigned char opcode;
 540         Sg_device *sdp;
 541         Sg_fd *sfp;
 542         Sg_request *srp;
 543         struct sg_header old_hdr;
 544         sg_io_hdr_t *hp;
 545         unsigned char cmnd[MAX_COMMAND_SIZE];
 546
 547         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 548                 return -ENXIO;
 549         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 550                                    sdp->disk->disk_name, (int) count));
 551         if (sdp->detached)
 552                 return -ENODEV;
 553         if (!((filp->f_flags & O_NONBLOCK) ||
 554               scsi_block_when_processing_errors(sdp->device)))
 555                 return -ENXIO;
 556
 557         if (!access_ok(VERIFY_READ, buf, count))
 558                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 559         if (count < SZ_SG_HEADER)
 560                 return -EIO;
 561         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 562                 return -EFAULT;
 563         blocking = !(filp->f_flags & O_NONBLOCK);
 564         if (old_hdr.reply_len < 0)
 565                 return sg_new_write(sfp, filp, buf, count, blocking, 0, NULL);
 566         if (count < (SZ_SG_HEADER + 6))
 567                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 568
 569         if (!(srp = sg_add_request(sfp))) {
 570                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 571                 return -EDOM;
 572         }
 573         buf += SZ_SG_HEADER;
 574         __get_user(opcode, buf);
 575         if (sfp->next_cmd_len > 0) {
 576                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 577                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 578                         sfp->next_cmd_len = 0;
 579                         sg_remove_request(sfp, srp);
 580                         return -EIO;
 581                 }
 582                 cmd_size = sfp->next_cmd_len;
 583                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 584         } else {
 585                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 586                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 587                         cmd_size = 12;
 588         }
 589         SCSI_LOG_TIMEOUT(4, printk(
 590                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 591 /* Determine buffer size.  */
 592         input_size = count - cmd_size;
 593         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 594         mxsize -= SZ_SG_HEADER;
 595         input_size -= SZ_SG_HEADER;
 596         if (input_size < 0) {
 597                 sg_remove_request(sfp, srp);
 598                 return -EIO;    /* User did not pass enough bytes for this command. */
 599         }
 600         hp = &srp->header;
 601         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 602         hp->cmd_len = (unsigned char) cmd_size;
 603         hp->iovec_count = 0;
 604         hp->mx_sb_len = 0;
 605         if (input_size > 0)
 606                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 607                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 608         else
 609                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 610         hp->dxfer_len = mxsize;
 611         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 612                 hp->dxferp = (char __user *)buf + cmd_size;
 613         else
 614                 hp->dxferp = NULL;
 615         hp->sbp = NULL;
 616         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 617         hp->flags = input_size; /* structure abuse ... */
 618         hp->pack_id = old_hdr.pack_id;
 619         hp->usr_ptr = NULL;
 620         if (__copy_from_user(cmnd, buf, cmd_size))
 621                 return -EFAULT;
 622         /*
 623          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 624          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 625          * is a non-zero input_size, so emit a warning.
 626          */
 627         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 628                 static char cmd[TASK_COMM_LEN];
 629                 if (strcmp(current->comm, cmd) && printk_ratelimit()) {
 630                         printk(KERN_WARNING
 631                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 632                                "guessing data in;\n" KERN_WARNING "   "
 633                                "program %s not setting count and/or reply_len properly\n",
 634                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 635                                input_size, (unsigned int) cmnd[0],
 636                                current->comm);
 637                         strcpy(cmd, current->comm);
 638                 }
 639         }
 640         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 641         return (k < 0) ? k : count;
 642 }
 643
 644 static ssize_t
 645 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 646                  size_t count, int blocking, int read_only,
 647                  Sg_request **o_srp)
 648 {
 649         int k;
 650         Sg_request *srp;
 651         sg_io_hdr_t *hp;
 652         unsigned char cmnd[MAX_COMMAND_SIZE];
 653         int timeout;
 654         unsigned long ul_timeout;
 655
 656         if (count < SZ_SG_IO_HDR)
 657                 return -EINVAL;
 658         if (!access_ok(VERIFY_READ, buf, count))
 659                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 660
 661         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 662         if (!(srp = sg_add_request(sfp))) {
 663                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 664                 return -EDOM;
 665         }
 666         hp = &srp->header;
 667         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 668                 sg_remove_request(sfp, srp);
 669                 return -EFAULT;
 670         }
 671         if (hp->interface_id != 'S') {
 672                 sg_remove_request(sfp, srp);
 673                 return -ENOSYS;
 674         }
 675         if (hp->flags & SG_FLAG_MMAP_IO) {
 676                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 677                         sg_remove_request(sfp, srp);
 678                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 679                 }
 680                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 681                         sg_remove_request(sfp, srp);
 682                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 683                 }
 684                 if (sg_res_in_use(sfp)) {
 685                         sg_remove_request(sfp, srp);
 686                         return -EBUSY;  /* reserve buffer already being used */
 687                 }
 688         }
 689         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 690         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 691         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 692                 sg_remove_request(sfp, srp);
 693                 return -EMSGSIZE;
 694         }
 695         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 696                 sg_remove_request(sfp, srp);
 697                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 698         }
 699         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 700                 sg_remove_request(sfp, srp);
 701                 return -EFAULT;
 702         }
 703         if (read_only && sg_allow_access(file, cmnd)) {
 704                 sg_remove_request(sfp, srp);
 705                 return -EPERM;
 706         }
 707         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 708         if (k < 0)
 709                 return k;
 710         if (o_srp)
 711                 *o_srp = srp;
 712         return count;
 713 }
 714
 715 static int
 716 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 717                 unsigned char *cmnd, int timeout, int blocking)
 718 {
 719         int k, data_dir;
 720         Sg_device *sdp = sfp->parentdp;
 721         sg_io_hdr_t *hp = &srp->header;
 722
 723         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 724         hp->status = 0;
 725         hp->masked_status = 0;
 726         hp->msg_status = 0;
 727         hp->info = 0;
 728         hp->host_status = 0;
 729         hp->driver_status = 0;
 730         hp->resid = 0;
 731         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 732                           (int) cmnd[0], (int) hp->cmd_len));
 733
 734         k = sg_start_req(srp, cmnd);
 735         if (k) {
 736                 SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 737                 sg_finish_rem_req(srp);
 738                 return k;       /* probably out of space --> ENOMEM */
 739         }
 740         if (sdp->detached) {
 741                 sg_finish_rem_req(srp);
 742                 return -ENODEV;
 743         }
 744
 745         switch (hp->dxfer_direction) {
 746         case SG_DXFER_TO_FROM_DEV:
 747         case SG_DXFER_FROM_DEV:
 748                 data_dir = DMA_FROM_DEVICE;
 749                 break;
 750         case SG_DXFER_TO_DEV:
 751                 data_dir = DMA_TO_DEVICE;
 752                 break;
 753         case SG_DXFER_UNKNOWN:
 754                 data_dir = DMA_BIDIRECTIONAL;
 755                 break;
 756         default:
 757                 data_dir = DMA_NONE;
 758                 break;
 759         }
 760         hp->duration = jiffies_to_msecs(jiffies);
 761
 762         srp->rq->timeout = timeout;
 763         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 764                               srp->rq, 1, sg_rq_end_io);
 765         return 0;
 766 }
 767
 768 static int
 769 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 770 {
 771         unsigned long iflags;
 772         int done;
 773
 774         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 775         done = srp->done;
 776         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 777         return done;
 778 }
 779
 780 static int
 781 sg_ioctl(struct inode *inode, struct file *filp,
 782          unsigned int cmd_in, unsigned long arg)
 783 {
 784         void __user *p = (void __user *)arg;
 785         int __user *ip = p;
 786         int result, val, read_only;
 787         Sg_device *sdp;
 788         Sg_fd *sfp;
 789         Sg_request *srp;
 790         unsigned long iflags;
 791
 792         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 793                 return -ENXIO;
 794
 795         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 796                                    sdp->disk->disk_name, (int) cmd_in));
 797         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 798
 799         switch (cmd_in) {
 800         case SG_IO:
 801                 {
 802                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 803
 804                         if (sdp->detached)
 805                                 return -ENODEV;
 806                         if (!scsi_block_when_processing_errors(sdp->device))
 807                                 return -ENXIO;
 808                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 809                                 return -EFAULT;
 810                         result =
 811                             sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 812                                          blocking, read_only, &srp);
 813                         if (result < 0)
 814                                 return result;
 815                         srp->sg_io_owned = 1;
 816                         while (1) {
 817                                 result = 0;     /* following macro to beat race condition */
 818                                 __wait_event_interruptible(sfp->read_wait,
 819                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 820                                                            result);
 821                                 if (sdp->detached)
 822                                         return -ENODEV;
 823                                 if (sfp->closed)
 824                                         return 0;       /* request packet dropped already */
 825                                 if (0 == result)
 826                                         break;
 827                                 srp->orphan = 1;
 828                                 return result;  /* -ERESTARTSYS because signal hit process */
 829                         }
 830                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 831                         srp->done = 2;
 832                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 833                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 834                         return (result < 0) ? result : 0;
 835                 }
 836         case SG_SET_TIMEOUT:
 837                 result = get_user(val, ip);
 838                 if (result)
 839                         return result;
 840                 if (val < 0)
 841                         return -EIO;
 842                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 843                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 844                 sfp->timeout_user = val;
 845                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 846
 847                 return 0;
 848         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 849                                 /* strange ..., for backward compatibility */
 850                 return sfp->timeout_user;
 851         case SG_SET_FORCE_LOW_DMA:
 852                 result = get_user(val, ip);
 853                 if (result)
 854                         return result;
 855                 if (val) {
 856                         sfp->low_dma = 1;
 857                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 858                                 val = (int) sfp->reserve.bufflen;
 859                                 sg_remove_scat(&sfp->reserve);
 860                                 sg_build_reserve(sfp, val);
 861                         }
 862                 } else {
 863                         if (sdp->detached)
 864                                 return -ENODEV;
 865                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 866                 }
 867                 return 0;
 868         case SG_GET_LOW_DMA:
 869                 return put_user((int) sfp->low_dma, ip);
 870         case SG_GET_SCSI_ID:
 871                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 872                         return -EFAULT;
 873                 else {
 874                         sg_scsi_id_t __user *sg_idp = p;
 875
 876                         if (sdp->detached)
 877                                 return -ENODEV;
 878                         __put_user((int) sdp->device->host->host_no,
 879                                    &sg_idp->host_no);
 880                         __put_user((int) sdp->device->channel,
 881                                    &sg_idp->channel);
 882                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 883                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 884                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 885                         __put_user((short) sdp->device->host->cmd_per_lun,
 886                                    &sg_idp->h_cmd_per_lun);
 887                         __put_user((short) sdp->device->queue_depth,
 888                                    &sg_idp->d_queue_depth);
 889                         __put_user(0, &sg_idp->unused[0]);
 890                         __put_user(0, &sg_idp->unused[1]);
 891                         return 0;
 892                 }
 893         case SG_SET_FORCE_PACK_ID:
 894                 result = get_user(val, ip);
 895                 if (result)
 896                         return result;
 897                 sfp->force_packid = val ? 1 : 0;
 898                 return 0;
 899         case SG_GET_PACK_ID:
 900                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 901                         return -EFAULT;
 902                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 903                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 904                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 905                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 906                                                        iflags);
 907                                 __put_user(srp->header.pack_id, ip);
 908                                 return 0;
 909                         }
 910                 }
 911                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 912                 __put_user(-1, ip);
 913                 return 0;
 914         case SG_GET_NUM_WAITING:
 915                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 916                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 917                         if ((1 == srp->done) && (!srp->sg_io_owned))
 918                                 ++val;
 919                 }
 920                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 921                 return put_user(val, ip);
 922         case SG_GET_SG_TABLESIZE:
 923                 return put_user(sdp->sg_tablesize, ip);
 924         case SG_SET_RESERVED_SIZE:
 925                 result = get_user(val, ip);
 926                 if (result)
 927                         return result;
 928                 if (val < 0)
 929                         return -EINVAL;
 930                 val = min_t(int, val,
 931                                 sdp->device->request_queue->max_sectors * 512);
 932                 if (val != sfp->reserve.bufflen) {
 933                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 934                                 return -EBUSY;
 935                         sg_remove_scat(&sfp->reserve);
 936                         sg_build_reserve(sfp, val);
 937                 }
 938                 return 0;
 939         case SG_GET_RESERVED_SIZE:
 940                 val = min_t(int, sfp->reserve.bufflen,
 941                                 sdp->device->request_queue->max_sectors * 512);
 942                 return put_user(val, ip);
 943         case SG_SET_COMMAND_Q:
 944                 result = get_user(val, ip);
 945                 if (result)
 946                         return result;
 947                 sfp->cmd_q = val ? 1 : 0;
 948                 return 0;
 949         case SG_GET_COMMAND_Q:
 950                 return put_user((int) sfp->cmd_q, ip);
 951         case SG_SET_KEEP_ORPHAN:
 952                 result = get_user(val, ip);
 953                 if (result)
 954                         return result;
 955                 sfp->keep_orphan = val;
 956                 return 0;
 957         case SG_GET_KEEP_ORPHAN:
 958                 return put_user((int) sfp->keep_orphan, ip);
 959         case SG_NEXT_CMD_LEN:
 960                 result = get_user(val, ip);
 961                 if (result)
 962                         return result;
 963                 sfp->next_cmd_len = (val > 0) ? val : 0;
 964                 return 0;
 965         case SG_GET_VERSION_NUM:
 966                 return put_user(sg_version_num, ip);
 967         case SG_GET_ACCESS_COUNT:
 968                 /* faked - we don't have a real access count anymore */
 969                 val = (sdp->device ? 1 : 0);
 970                 return put_user(val, ip);
 971         case SG_GET_REQUEST_TABLE:
 972                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 973                         return -EFAULT;
 974                 else {
 975                         sg_req_info_t *rinfo;
 976                         unsigned int ms;
 977
 978                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 979                                                                 GFP_KERNEL);
 980                         if (!rinfo)
 981                                 return -ENOMEM;
 982                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 983                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 984                              ++val, srp = srp ? srp->nextrp : srp) {
 985                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 986                                 if (srp) {
 987                                         rinfo[val].req_state = srp->done + 1;
 988                                         rinfo[val].problem =
 989                                             srp->header.masked_status &
 990                                             srp->header.host_status &
 991                                             srp->header.driver_status;
 992                                         if (srp->done)
 993                                                 rinfo[val].duration =
 994                                                         srp->header.duration;
 995                                         else {
 996                                                 ms = jiffies_to_msecs(jiffies);
 997                                                 rinfo[val].duration =
 998                                                     (ms > srp->header.duration) ?
 999                                                     (ms - srp->header.duration) : 0;
1000                                         }
1001                                         rinfo[val].orphan = srp->orphan;
1002                                         rinfo[val].sg_io_owned =
1003                                                         srp->sg_io_owned;
1004                                         rinfo[val].pack_id =
1005                                                         srp->header.pack_id;
1006                                         rinfo[val].usr_ptr =
1007                                                         srp->header.usr_ptr;
1008                                 }
1009                         }
1010                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1011                         result = __copy_to_user(p, rinfo,
1012                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1013                         result = result ? -EFAULT : 0;
1014                         kfree(rinfo);
1015                         return result;
1016                 }
1017         case SG_EMULATED_HOST:
1018                 if (sdp->detached)
1019                         return -ENODEV;
1020                 return put_user(sdp->device->host->hostt->emulated, ip);
1021         case SG_SCSI_RESET:
1022                 if (sdp->detached)
1023                         return -ENODEV;
1024                 if (filp->f_flags & O_NONBLOCK) {
1025                         if (scsi_host_in_recovery(sdp->device->host))
1026                                 return -EBUSY;
1027                 } else if (!scsi_block_when_processing_errors(sdp->device))
1028                         return -EBUSY;
1029                 result = get_user(val, ip);
1030                 if (result)
1031                         return result;
1032                 if (SG_SCSI_RESET_NOTHING == val)
1033                         return 0;
1034                 switch (val) {
1035                 case SG_SCSI_RESET_DEVICE:
1036                         val = SCSI_TRY_RESET_DEVICE;
1037                         break;
1038                 case SG_SCSI_RESET_TARGET:
1039                         val = SCSI_TRY_RESET_TARGET;
1040                         break;
1041                 case SG_SCSI_RESET_BUS:
1042                         val = SCSI_TRY_RESET_BUS;
1043                         break;
1044                 case SG_SCSI_RESET_HOST:
1045                         val = SCSI_TRY_RESET_HOST;
1046                         break;
1047                 default:
1048                         return -EINVAL;
1049                 }
1050                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1051                         return -EACCES;
1052                 return (scsi_reset_provider(sdp->device, val) ==
1053                         SUCCESS) ? 0 : -EIO;
1054         case SCSI_IOCTL_SEND_COMMAND:
1055                 if (sdp->detached)
1056                         return -ENODEV;
1057                 if (read_only) {
1058                         unsigned char opcode = WRITE_6;
1059                         Scsi_Ioctl_Command __user *siocp = p;
1060
1061                         if (copy_from_user(&opcode, siocp->data, 1))
1062                                 return -EFAULT;
1063                         if (sg_allow_access(filp, &opcode))
1064                                 return -EPERM;
1065                 }
1066                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1067         case SG_SET_DEBUG:
1068                 result = get_user(val, ip);
1069                 if (result)
1070                         return result;
1071                 sdp->sgdebug = (char) val;
1072                 return 0;
1073         case SCSI_IOCTL_GET_IDLUN:
1074         case SCSI_IOCTL_GET_BUS_NUMBER:
1075         case SCSI_IOCTL_PROBE_HOST:
1076         case SG_GET_TRANSFORM:
1077                 if (sdp->detached)
1078                         return -ENODEV;
1079                 return scsi_ioctl(sdp->device, cmd_in, p);
1080         case BLKSECTGET:
1081                 return put_user(sdp->device->request_queue->max_sectors * 512,
1082                                 ip);
1083         case BLKTRACESETUP:
1084                 return blk_trace_setup(sdp->device->request_queue,
1085                                        sdp->disk->disk_name,
1086                                        sdp->device->sdev_gendev.devt,
1087                                        (char *)arg);
1088         case BLKTRACESTART:
1089                 return blk_trace_startstop(sdp->device->request_queue, 1);
1090         case BLKTRACESTOP:
1091                 return blk_trace_startstop(sdp->device->request_queue, 0);
1092         case BLKTRACETEARDOWN:
1093                 return blk_trace_remove(sdp->device->request_queue);
1094         default:
1095                 if (read_only)
1096                         return -EPERM;  /* don't know so take safe approach */
1097                 return scsi_ioctl(sdp->device, cmd_in, p);
1098         }
1099 }
1100
1101 #ifdef CONFIG_COMPAT
1102 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1103 {
1104         Sg_device *sdp;
1105         Sg_fd *sfp;
1106         struct scsi_device *sdev;
1107
1108         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1109                 return -ENXIO;
1110
1111         sdev = sdp->device;
1112         if (sdev->host->hostt->compat_ioctl) {
1113                 int ret;
1114
1115                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1116
1117                 return ret;
1118         }
1119
1120         return -ENOIOCTLCMD;
1121 }
1122 #endif
1123
1124 static unsigned int
1125 sg_poll(struct file *filp, poll_table * wait)
1126 {
1127         unsigned int res = 0;
1128         Sg_device *sdp;
1129         Sg_fd *sfp;
1130         Sg_request *srp;
1131         int count = 0;
1132         unsigned long iflags;
1133
1134         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1135             || sfp->closed)
1136                 return POLLERR;
1137         poll_wait(filp, &sfp->read_wait, wait);
1138         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1139         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1140                 /* if any read waiting, flag it */
1141                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1142                         res = POLLIN | POLLRDNORM;
1143                 ++count;
1144         }
1145         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1146
1147         if (sdp->detached)
1148                 res |= POLLHUP;
1149         else if (!sfp->cmd_q) {
1150                 if (0 == count)
1151                         res |= POLLOUT | POLLWRNORM;
1152         } else if (count < SG_MAX_QUEUE)
1153                 res |= POLLOUT | POLLWRNORM;
1154         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1155                                    sdp->disk->disk_name, (int) res));
1156         return res;
1157 }
1158
1159 static int
1160 sg_fasync(int fd, struct file *filp, int mode)
1161 {
1162         int retval;
1163         Sg_device *sdp;
1164         Sg_fd *sfp;
1165
1166         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1167                 return -ENXIO;
1168         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1169                                    sdp->disk->disk_name, mode));
1170
1171         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1172         return (retval < 0) ? retval : 0;
1173 }
1174
1175 static int
1176 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1177 {
1178         Sg_fd *sfp;
1179         unsigned long offset, len, sa;
1180         Sg_scatter_hold *rsv_schp;
1181         int k, length;
1182
1183         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1184                 return VM_FAULT_SIGBUS;
1185         rsv_schp = &sfp->reserve;
1186         offset = vmf->pgoff << PAGE_SHIFT;
1187         if (offset >= rsv_schp->bufflen)
1188                 return VM_FAULT_SIGBUS;
1189         SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1190                                    offset, rsv_schp->k_use_sg));
1191         sa = vma->vm_start;
1192         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1193         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1194                 len = vma->vm_end - sa;
1195                 len = (len < length) ? len : length;
1196                 if (offset < len) {
1197                         struct page *page = nth_page(rsv_schp->pages[k],
1198                                                      offset >> PAGE_SHIFT);
1199                         get_page(page); /* increment page count */
1200                         vmf->page = page;
1201                         return 0; /* success */
1202                 }
1203                 sa += len;
1204                 offset -= len;
1205         }
1206
1207         return VM_FAULT_SIGBUS;
1208 }
1209
1210 static struct vm_operations_struct sg_mmap_vm_ops = {
1211         .fault = sg_vma_fault,
1212 };
1213
1214 static int
1215 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1216 {
1217         Sg_fd *sfp;
1218         unsigned long req_sz, len, sa;
1219         Sg_scatter_hold *rsv_schp;
1220         int k, length;
1221
1222         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1223                 return -ENXIO;
1224         req_sz = vma->vm_end - vma->vm_start;
1225         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1226                                    (void *) vma->vm_start, (int) req_sz));
1227         if (vma->vm_pgoff)
1228                 return -EINVAL; /* want no offset */
1229         rsv_schp = &sfp->reserve;
1230         if (req_sz > rsv_schp->bufflen)
1231                 return -ENOMEM; /* cannot map more than reserved buffer */
1232
1233         sa = vma->vm_start;
1234         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1235         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1236                 len = vma->vm_end - sa;
1237                 len = (len < length) ? len : length;
1238                 sa += len;
1239         }
1240
1241         sfp->mmap_called = 1;
1242         vma->vm_flags |= VM_RESERVED;
1243         vma->vm_private_data = sfp;
1244         vma->vm_ops = &sg_mmap_vm_ops;
1245         return 0;
1246 }
1247
1248 /*
1249  * This function is a "bottom half" handler that is called by the mid
1250  * level when a command is completed (or has failed).
1251  */
1252 static void sg_rq_end_io(struct request *rq, int uptodate)
1253 {
1254         struct sg_request *srp = rq->end_io_data;
1255         Sg_device *sdp = NULL;
1256         Sg_fd *sfp;
1257         unsigned long iflags;
1258         unsigned int ms;
1259         char *sense;
1260         int result, resid;
1261
1262         if (NULL == srp) {
1263                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1264                 return;
1265         }
1266         sfp = srp->parentfp;
1267         if (sfp)
1268                 sdp = sfp->parentdp;
1269         if ((NULL == sdp) || sdp->detached) {
1270                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1271                 return;
1272         }
1273
1274         sense = rq->sense;
1275         result = rq->errors;
1276         resid = rq->data_len;
1277
1278         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1279                 sdp->disk->disk_name, srp->header.pack_id, result));
1280         srp->header.resid = resid;
1281         ms = jiffies_to_msecs(jiffies);
1282         srp->header.duration = (ms > srp->header.duration) ?
1283                                 (ms - srp->header.duration) : 0;
1284         if (0 != result) {
1285                 struct scsi_sense_hdr sshdr;
1286
1287                 srp->header.status = 0xff & result;
1288                 srp->header.masked_status = status_byte(result);
1289                 srp->header.msg_status = msg_byte(result);
1290                 srp->header.host_status = host_byte(result);
1291                 srp->header.driver_status = driver_byte(result);
1292                 if ((sdp->sgdebug > 0) &&
1293                     ((CHECK_CONDITION == srp->header.masked_status) ||
1294                      (COMMAND_TERMINATED == srp->header.masked_status)))
1295                         __scsi_print_sense("sg_cmd_done", sense,
1296                                            SCSI_SENSE_BUFFERSIZE);
1297
1298                 /* Following if statement is a patch supplied by Eric Youngdale */
1299                 if (driver_byte(result) != 0
1300                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1301                     && !scsi_sense_is_deferred(&sshdr)
1302                     && sshdr.sense_key == UNIT_ATTENTION
1303                     && sdp->device->removable) {
1304                         /* Detected possible disc change. Set the bit - this */
1305                         /* may be used if there are filesystems using this device */
1306                         sdp->device->changed = 1;
1307                 }
1308         }
1309         /* Rely on write phase to clean out srp status values, so no "else" */
1310
1311         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1312                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1313                 sg_finish_rem_req(srp);
1314                 srp = NULL;
1315                 if (NULL == sfp->headrp) {
1316                         SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1317                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1318                                 scsi_device_put(sdp->device);
1319                         }
1320                         sfp = NULL;
1321                 }
1322         } else if (srp && srp->orphan) {
1323                 if (sfp->keep_orphan)
1324                         srp->sg_io_owned = 0;
1325                 else {
1326                         sg_finish_rem_req(srp);
1327                         srp = NULL;
1328                 }
1329         }
1330         if (sfp && srp) {
1331                 /* Now wake up any sg_read() that is waiting for this packet. */
1332                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1333                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1334                 srp->done = 1;
1335                 wake_up_interruptible(&sfp->read_wait);
1336                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1337         }
1338 }
1339
1340 static struct file_operations sg_fops = {
1341         .owner = THIS_MODULE,
1342         .read = sg_read,
1343         .write = sg_write,
1344         .poll = sg_poll,
1345         .ioctl = sg_ioctl,
1346 #ifdef CONFIG_COMPAT
1347         .compat_ioctl = sg_compat_ioctl,
1348 #endif
1349         .open = sg_open,
1350         .mmap = sg_mmap,
1351         .release = sg_release,
1352         .fasync = sg_fasync,
1353 };
1354
1355 static struct class *sg_sysfs_class;
1356
1357 static int sg_sysfs_valid = 0;
1358
1359 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1360 {
1361         struct request_queue *q = scsidp->request_queue;
1362         Sg_device *sdp;
1363         unsigned long iflags;
1364         int error;
1365         u32 k;
1366
1367         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1368         if (!sdp) {
1369                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1370                 return ERR_PTR(-ENOMEM);
1371         }
1372         error = -ENOMEM;
1373         if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1374                 printk(KERN_WARNING "idr expansion Sg_device failure\n");
1375                 goto out;
1376         }
1377
1378         write_lock_irqsave(&sg_index_lock, iflags);
1379         error = idr_get_new(&sg_index_idr, sdp, &k);
1380         write_unlock_irqrestore(&sg_index_lock, iflags);
1381
1382         if (error) {
1383                 printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1384                        error);
1385                 goto out;
1386         }
1387
1388         if (unlikely(k >= SG_MAX_DEVS))
1389                 goto overflow;
1390
1391         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1392         sprintf(disk->disk_name, "sg%d", k);
1393         disk->first_minor = k;
1394         sdp->disk = disk;
1395         sdp->device = scsidp;
1396         init_waitqueue_head(&sdp->o_excl_wait);
1397         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1398         sdp->index = k;
1399
1400         error = 0;
1401  out:
1402         if (error) {
1403                 kfree(sdp);
1404                 return ERR_PTR(error);
1405         }
1406         return sdp;
1407
1408  overflow:
1409         sdev_printk(KERN_WARNING, scsidp,
1410                     "Unable to attach sg device type=%d, minor "
1411                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1412         error = -ENODEV;
1413         goto out;
1414 }
1415
1416 static int
1417 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1418 {
1419         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1420         struct gendisk *disk;
1421         Sg_device *sdp = NULL;
1422         struct cdev * cdev = NULL;
1423         int error;
1424         unsigned long iflags;
1425
1426         disk = alloc_disk(1);
1427         if (!disk) {
1428                 printk(KERN_WARNING "alloc_disk failed\n");
1429                 return -ENOMEM;
1430         }
1431         disk->major = SCSI_GENERIC_MAJOR;
1432
1433         error = -ENOMEM;
1434         cdev = cdev_alloc();
1435         if (!cdev) {
1436                 printk(KERN_WARNING "cdev_alloc failed\n");
1437                 goto out;
1438         }
1439         cdev->owner = THIS_MODULE;
1440         cdev->ops = &sg_fops;
1441
1442         sdp = sg_alloc(disk, scsidp);
1443         if (IS_ERR(sdp)) {
1444                 printk(KERN_WARNING "sg_alloc failed\n");
1445                 error = PTR_ERR(sdp);
1446                 goto out;
1447         }
1448
1449         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1450         if (error)
1451                 goto cdev_add_err;
1452
1453         sdp->cdev = cdev;
1454         if (sg_sysfs_valid) {
1455                 struct device *sg_class_member;
1456
1457                 sg_class_member = device_create_drvdata(sg_sysfs_class,
1458                                                         cl_dev->parent,
1459                                                         MKDEV(SCSI_GENERIC_MAJOR,
1460                                                               sdp->index),
1461                                                         sdp,
1462                                                         "%s", disk->disk_name);
1463                 if (IS_ERR(sg_class_member)) {
1464                         printk(KERN_ERR "sg_add: "
1465                                "device_create failed\n");
1466                         error = PTR_ERR(sg_class_member);
1467                         goto cdev_add_err;
1468                 }
1469                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1470                                           &sg_class_member->kobj, "generic");
1471                 if (error)
1472                         printk(KERN_ERR "sg_add: unable to make symlink "
1473                                         "'generic' back to sg%d\n", sdp->index);
1474         } else
1475                 printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1476
1477         sdev_printk(KERN_NOTICE, scsidp,
1478                     "Attached scsi generic sg%d type %d\n", sdp->index,
1479                     scsidp->type);
1480
1481         dev_set_drvdata(cl_dev, sdp);
1482
1483         return 0;
1484
1485 cdev_add_err:
1486         write_lock_irqsave(&sg_index_lock, iflags);
1487         idr_remove(&sg_index_idr, sdp->index);
1488         write_unlock_irqrestore(&sg_index_lock, iflags);
1489         kfree(sdp);
1490
1491 out:
1492         put_disk(disk);
1493         if (cdev)
1494                 cdev_del(cdev);
1495         return error;
1496 }
1497
1498 static void
1499 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1500 {
1501         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1502         Sg_device *sdp = dev_get_drvdata(cl_dev);
1503         unsigned long iflags;
1504         Sg_fd *sfp;
1505         Sg_fd *tsfp;
1506         Sg_request *srp;
1507         Sg_request *tsrp;
1508         int delay;
1509
1510         if (!sdp)
1511                 return;
1512
1513         delay = 0;
1514         write_lock_irqsave(&sg_index_lock, iflags);
1515         if (sdp->headfp) {
1516                 sdp->detached = 1;
1517                 for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1518                         tsfp = sfp->nextfp;
1519                         for (srp = sfp->headrp; srp; srp = tsrp) {
1520                                 tsrp = srp->nextrp;
1521                                 if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1522                                         sg_finish_rem_req(srp);
1523                         }
1524                         if (sfp->closed) {
1525                                 scsi_device_put(sdp->device);
1526                                 __sg_remove_sfp(sdp, sfp);
1527                         } else {
1528                                 delay = 1;
1529                                 wake_up_interruptible(&sfp->read_wait);
1530                                 kill_fasync(&sfp->async_qp, SIGPOLL,
1531                                             POLL_HUP);
1532                         }
1533                 }
1534                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1535                 if (NULL == sdp->headfp) {
1536                         idr_remove(&sg_index_idr, sdp->index);
1537                 }
1538         } else {        /* nothing active, simple case */
1539                 SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1540                 idr_remove(&sg_index_idr, sdp->index);
1541         }
1542         write_unlock_irqrestore(&sg_index_lock, iflags);
1543
1544         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1545         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1546         cdev_del(sdp->cdev);
1547         sdp->cdev = NULL;
1548         put_disk(sdp->disk);
1549         sdp->disk = NULL;
1550         if (NULL == sdp->headfp)
1551                 kfree(sdp);
1552
1553         if (delay)
1554                 msleep(10);     /* dirty detach so delay device destruction */
1555 }
1556
1557 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1558 module_param_named(def_reserved_size, def_reserved_size, int,
1559                    S_IRUGO | S_IWUSR);
1560 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1561
1562 MODULE_AUTHOR("Douglas Gilbert");
1563 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1564 MODULE_LICENSE("GPL");
1565 MODULE_VERSION(SG_VERSION_STR);
1566 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1567
1568 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1569                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1570 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1571 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1572
1573 static int __init
1574 init_sg(void)
1575 {
1576         int rc;
1577
1578         if (scatter_elem_sz < PAGE_SIZE) {
1579                 scatter_elem_sz = PAGE_SIZE;
1580                 scatter_elem_sz_prev = scatter_elem_sz;
1581         }
1582         if (def_reserved_size >= 0)
1583                 sg_big_buff = def_reserved_size;
1584         else
1585                 def_reserved_size = sg_big_buff;
1586
1587         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1588                                     SG_MAX_DEVS, "sg");
1589         if (rc)
1590                 return rc;
1591         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1592         if ( IS_ERR(sg_sysfs_class) ) {
1593                 rc = PTR_ERR(sg_sysfs_class);
1594                 goto err_out;
1595         }
1596         sg_sysfs_valid = 1;
1597         rc = scsi_register_interface(&sg_interface);
1598         if (0 == rc) {
1599 #ifdef CONFIG_SCSI_PROC_FS
1600                 sg_proc_init();
1601 #endif                          /* CONFIG_SCSI_PROC_FS */
1602                 return 0;
1603         }
1604         class_destroy(sg_sysfs_class);
1605 err_out:
1606         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1607         return rc;
1608 }
1609
1610 static void __exit
1611 exit_sg(void)
1612 {
1613 #ifdef CONFIG_SCSI_PROC_FS
1614         sg_proc_cleanup();
1615 #endif                          /* CONFIG_SCSI_PROC_FS */
1616         scsi_unregister_interface(&sg_interface);
1617         class_destroy(sg_sysfs_class);
1618         sg_sysfs_valid = 0;
1619         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1620                                  SG_MAX_DEVS);
1621         idr_destroy(&sg_index_idr);
1622 }
1623
1624 static int sg_start_req(Sg_request *srp, unsigned char *cmd)
1625 {
1626         int res;
1627         struct request *rq;
1628         Sg_fd *sfp = srp->parentfp;
1629         sg_io_hdr_t *hp = &srp->header;
1630         int dxfer_len = (int) hp->dxfer_len;
1631         int dxfer_dir = hp->dxfer_direction;
1632         unsigned int iov_count = hp->iovec_count;
1633         Sg_scatter_hold *req_schp = &srp->data;
1634         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1635         struct request_queue *q = sfp->parentdp->device->request_queue;
1636         struct rq_map_data *md, map_data;
1637         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1638
1639         SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
1640                                    dxfer_len));
1641
1642         rq = blk_get_request(q, rw, GFP_ATOMIC);
1643         if (!rq)
1644                 return -ENOMEM;
1645
1646         memcpy(rq->cmd, cmd, hp->cmd_len);
1647
1648         rq->cmd_len = hp->cmd_len;
1649         rq->cmd_type = REQ_TYPE_BLOCK_PC;
1650
1651         srp->rq = rq;
1652         rq->end_io_data = srp;
1653         rq->sense = srp->sense_b;
1654         rq->retries = SG_DEFAULT_RETRIES;
1655
1656         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1657                 return 0;
1658
1659         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1660             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1661             !sfp->parentdp->device->host->unchecked_isa_dma &&
1662             blk_rq_aligned(q, hp->dxferp, dxfer_len))
1663                 md = NULL;
1664         else
1665                 md = &map_data;
1666
1667         if (md) {
1668                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1669                         sg_link_reserve(sfp, srp, dxfer_len);
1670                 else {
1671                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1672                         if (res)
1673                                 return res;
1674                 }
1675
1676                 md->pages = req_schp->pages;
1677                 md->page_order = req_schp->page_order;
1678                 md->nr_entries = req_schp->k_use_sg;
1679         }
1680
1681         if (iov_count)
1682                 res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count,
1683                                           hp->dxfer_len, GFP_ATOMIC);
1684         else
1685                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1686                                       hp->dxfer_len, GFP_ATOMIC);
1687
1688         if (!res) {
1689                 srp->bio = rq->bio;
1690
1691                 if (!md) {
1692                         req_schp->dio_in_use = 1;
1693                         hp->info |= SG_INFO_DIRECT_IO;
1694                 }
1695         }
1696         return res;
1697 }
1698
1699 static void
1700 sg_finish_rem_req(Sg_request * srp)
1701 {
1702         Sg_fd *sfp = srp->parentfp;
1703         Sg_scatter_hold *req_schp = &srp->data;
1704
1705         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1706         if (srp->res_used)
1707                 sg_unlink_reserve(sfp, srp);
1708         else
1709                 sg_remove_scat(req_schp);
1710
1711         if (srp->rq) {
1712                 if (srp->bio)
1713                         blk_rq_unmap_user(srp->bio);
1714
1715                 blk_put_request(srp->rq);
1716         }
1717
1718         sg_remove_request(sfp, srp);
1719 }
1720
1721 static int
1722 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1723 {
1724         int sg_bufflen = tablesize * sizeof(struct page *);
1725         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1726
1727         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1728         if (!schp->pages)
1729                 return -ENOMEM;
1730         schp->sglist_len = sg_bufflen;
1731         return tablesize;       /* number of scat_gath elements allocated */
1732 }
1733
1734 static int
1735 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1736 {
1737         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1738         int sg_tablesize = sfp->parentdp->sg_tablesize;
1739         int blk_size = buff_size, order;
1740         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1741
1742         if (blk_size < 0)
1743                 return -EFAULT;
1744         if (0 == blk_size)
1745                 ++blk_size;     /* don't know why */
1746 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1747         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1748         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1749                                    buff_size, blk_size));
1750
1751         /* N.B. ret_sz carried into this block ... */
1752         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1753         if (mx_sc_elems < 0)
1754                 return mx_sc_elems;     /* most likely -ENOMEM */
1755
1756         num = scatter_elem_sz;
1757         if (unlikely(num != scatter_elem_sz_prev)) {
1758                 if (num < PAGE_SIZE) {
1759                         scatter_elem_sz = PAGE_SIZE;
1760                         scatter_elem_sz_prev = PAGE_SIZE;
1761                 } else
1762                         scatter_elem_sz_prev = num;
1763         }
1764
1765         if (sfp->low_dma)
1766                 gfp_mask |= GFP_DMA;
1767
1768         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1769                 gfp_mask |= __GFP_ZERO;
1770
1771         order = get_order(num);
1772 retry:
1773         ret_sz = 1 << (PAGE_SHIFT + order);
1774
1775         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1776              k++, rem_sz -= ret_sz) {
1777
1778                 num = (rem_sz > scatter_elem_sz_prev) ?
1779                         scatter_elem_sz_prev : rem_sz;
1780
1781                 schp->pages[k] = alloc_pages(gfp_mask, order);
1782                 if (!schp->pages[k])
1783                         goto out;
1784
1785                 if (num == scatter_elem_sz_prev) {
1786                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1787                                 scatter_elem_sz = ret_sz;
1788                                 scatter_elem_sz_prev = ret_sz;
1789                         }
1790                 }
1791
1792                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1793                                  "ret_sz=%d\n", k, num, ret_sz));
1794         }               /* end of for loop */
1795
1796         schp->page_order = order;
1797         schp->k_use_sg = k;
1798         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1799                          "rem_sz=%d\n", k, rem_sz));
1800
1801         schp->bufflen = blk_size;
1802         if (rem_sz > 0) /* must have failed */
1803                 return -ENOMEM;
1804         return 0;
1805 out:
1806         for (i = 0; i < k; i++)
1807                 __free_pages(schp->pages[k], order);
1808
1809         if (--order >= 0)
1810                 goto retry;
1811
1812         return -ENOMEM;
1813 }
1814
1815 static void
1816 sg_remove_scat(Sg_scatter_hold * schp)
1817 {
1818         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1819         if (schp->pages && schp->sglist_len > 0) {
1820                 if (!schp->dio_in_use) {
1821                         int k;
1822
1823                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1824                                 SCSI_LOG_TIMEOUT(5, printk(
1825                                     "sg_remove_scat: k=%d, pg=0x%p\n",
1826                                     k, schp->pages[k]));
1827                                 __free_pages(schp->pages[k], schp->page_order);
1828                         }
1829
1830                         kfree(schp->pages);
1831                 }
1832         }
1833         memset(schp, 0, sizeof (*schp));
1834 }
1835
1836 static int
1837 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1838 {
1839         Sg_scatter_hold *schp = &srp->data;
1840         int k, num;
1841
1842         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
1843                                    num_read_xfer));
1844         if ((!outp) || (num_read_xfer <= 0))
1845                 return 0;
1846
1847         blk_rq_unmap_user(srp->bio);
1848         srp->bio = NULL;
1849
1850         num = 1 << (PAGE_SHIFT + schp->page_order);
1851         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1852                 if (num > num_read_xfer) {
1853                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1854                                            num_read_xfer))
1855                                 return -EFAULT;
1856                         break;
1857                 } else {
1858                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1859                                            num))
1860                                 return -EFAULT;
1861                         num_read_xfer -= num;
1862                         if (num_read_xfer <= 0)
1863                                 break;
1864                         outp += num;
1865                 }
1866         }
1867
1868         return 0;
1869 }
1870
1871 static void
1872 sg_build_reserve(Sg_fd * sfp, int req_size)
1873 {
1874         Sg_scatter_hold *schp = &sfp->reserve;
1875
1876         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
1877         do {
1878                 if (req_size < PAGE_SIZE)
1879                         req_size = PAGE_SIZE;
1880                 if (0 == sg_build_indirect(schp, sfp, req_size))
1881                         return;
1882                 else
1883                         sg_remove_scat(schp);
1884                 req_size >>= 1; /* divide by 2 */
1885         } while (req_size > (PAGE_SIZE / 2));
1886 }
1887
1888 static void
1889 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1890 {
1891         Sg_scatter_hold *req_schp = &srp->data;
1892         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1893         int k, num, rem;
1894
1895         srp->res_used = 1;
1896         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
1897         rem = size;
1898
1899         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1900         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1901                 if (rem <= num) {
1902                         req_schp->k_use_sg = k + 1;
1903                         req_schp->sglist_len = rsv_schp->sglist_len;
1904                         req_schp->pages = rsv_schp->pages;
1905
1906                         req_schp->bufflen = size;
1907                         req_schp->page_order = rsv_schp->page_order;
1908                         break;
1909                 } else
1910                         rem -= num;
1911         }
1912
1913         if (k >= rsv_schp->k_use_sg)
1914                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
1915 }
1916
1917 static void
1918 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
1919 {
1920         Sg_scatter_hold *req_schp = &srp->data;
1921
1922         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
1923                                    (int) req_schp->k_use_sg));
1924         req_schp->k_use_sg = 0;
1925         req_schp->bufflen = 0;
1926         req_schp->pages = NULL;
1927         req_schp->page_order = 0;
1928         req_schp->sglist_len = 0;
1929         sfp->save_scat_len = 0;
1930         srp->res_used = 0;
1931 }
1932
1933 static Sg_request *
1934 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
1935 {
1936         Sg_request *resp;
1937         unsigned long iflags;
1938
1939         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1940         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
1941                 /* look for requests that are ready + not SG_IO owned */
1942                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
1943                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
1944                         resp->done = 2; /* guard against other readers */
1945                         break;
1946                 }
1947         }
1948         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1949         return resp;
1950 }
1951
1952 #ifdef CONFIG_SCSI_PROC_FS
1953 static Sg_request *
1954 sg_get_nth_request(Sg_fd * sfp, int nth)
1955 {
1956         Sg_request *resp;
1957         unsigned long iflags;
1958         int k;
1959
1960         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1961         for (k = 0, resp = sfp->headrp; resp && (k < nth);
1962              ++k, resp = resp->nextrp) ;
1963         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1964         return resp;
1965 }
1966 #endif
1967
1968 /* always adds to end of list */
1969 static Sg_request *
1970 sg_add_request(Sg_fd * sfp)
1971 {
1972         int k;
1973         unsigned long iflags;
1974         Sg_request *resp;
1975         Sg_request *rp = sfp->req_arr;
1976
1977         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1978         resp = sfp->headrp;
1979         if (!resp) {
1980                 memset(rp, 0, sizeof (Sg_request));
1981                 rp->parentfp = sfp;
1982                 resp = rp;
1983                 sfp->headrp = resp;
1984         } else {
1985                 if (0 == sfp->cmd_q)
1986                         resp = NULL;    /* command queuing disallowed */
1987                 else {
1988                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
1989                                 if (!rp->parentfp)
1990                                         break;
1991                         }
1992                         if (k < SG_MAX_QUEUE) {
1993                                 memset(rp, 0, sizeof (Sg_request));
1994                                 rp->parentfp = sfp;
1995                                 while (resp->nextrp)
1996                                         resp = resp->nextrp;
1997                                 resp->nextrp = rp;
1998                                 resp = rp;
1999                         } else
2000                                 resp = NULL;
2001                 }
2002         }
2003         if (resp) {
2004                 resp->nextrp = NULL;
2005                 resp->header.duration = jiffies_to_msecs(jiffies);
2006         }
2007         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2008         return resp;
2009 }
2010
2011 /* Return of 1 for found; 0 for not found */
2012 static int
2013 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2014 {
2015         Sg_request *prev_rp;
2016         Sg_request *rp;
2017         unsigned long iflags;
2018         int res = 0;
2019
2020         if ((!sfp) || (!srp) || (!sfp->headrp))
2021                 return res;
2022         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2023         prev_rp = sfp->headrp;
2024         if (srp == prev_rp) {
2025                 sfp->headrp = prev_rp->nextrp;
2026                 prev_rp->parentfp = NULL;
2027                 res = 1;
2028         } else {
2029                 while ((rp = prev_rp->nextrp)) {
2030                         if (srp == rp) {
2031                                 prev_rp->nextrp = rp->nextrp;
2032                                 rp->parentfp = NULL;
2033                                 res = 1;
2034                                 break;
2035                         }
2036                         prev_rp = rp;
2037                 }
2038         }
2039         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2040         return res;
2041 }
2042
2043 #ifdef CONFIG_SCSI_PROC_FS
2044 static Sg_fd *
2045 sg_get_nth_sfp(Sg_device * sdp, int nth)
2046 {
2047         Sg_fd *resp;
2048         unsigned long iflags;
2049         int k;
2050
2051         read_lock_irqsave(&sg_index_lock, iflags);
2052         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2053              ++k, resp = resp->nextfp) ;
2054         read_unlock_irqrestore(&sg_index_lock, iflags);
2055         return resp;
2056 }
2057 #endif
2058
2059 static Sg_fd *
2060 sg_add_sfp(Sg_device * sdp, int dev)
2061 {
2062         Sg_fd *sfp;
2063         unsigned long iflags;
2064         int bufflen;
2065
2066         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2067         if (!sfp)
2068                 return NULL;
2069
2070         init_waitqueue_head(&sfp->read_wait);
2071         rwlock_init(&sfp->rq_list_lock);
2072
2073         sfp->timeout = SG_DEFAULT_TIMEOUT;
2074         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2075         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2076         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2077             sdp->device->host->unchecked_isa_dma : 1;
2078         sfp->cmd_q = SG_DEF_COMMAND_Q;
2079         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2080         sfp->parentdp = sdp;
2081         write_lock_irqsave(&sg_index_lock, iflags);
2082         if (!sdp->headfp)
2083                 sdp->headfp = sfp;
2084         else {                  /* add to tail of existing list */
2085                 Sg_fd *pfp = sdp->headfp;
2086                 while (pfp->nextfp)
2087                         pfp = pfp->nextfp;
2088                 pfp->nextfp = sfp;
2089         }
2090         write_unlock_irqrestore(&sg_index_lock, iflags);
2091         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2092         if (unlikely(sg_big_buff != def_reserved_size))
2093                 sg_big_buff = def_reserved_size;
2094
2095         bufflen = min_t(int, sg_big_buff,
2096                         sdp->device->request_queue->max_sectors * 512);
2097         sg_build_reserve(sfp, bufflen);
2098         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2099                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2100         return sfp;
2101 }
2102
2103 static void
2104 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2105 {
2106         Sg_fd *fp;
2107         Sg_fd *prev_fp;
2108
2109         prev_fp = sdp->headfp;
2110         if (sfp == prev_fp)
2111                 sdp->headfp = prev_fp->nextfp;
2112         else {
2113                 while ((fp = prev_fp->nextfp)) {
2114                         if (sfp == fp) {
2115                                 prev_fp->nextfp = fp->nextfp;
2116                                 break;
2117                         }
2118                         prev_fp = fp;
2119                 }
2120         }
2121         if (sfp->reserve.bufflen > 0) {
2122                 SCSI_LOG_TIMEOUT(6,
2123                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2124                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2125                 sg_remove_scat(&sfp->reserve);
2126         }
2127         sfp->parentdp = NULL;
2128         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2129         kfree(sfp);
2130 }
2131
2132 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2133 static int
2134 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2135 {
2136         Sg_request *srp;
2137         Sg_request *tsrp;
2138         int dirty = 0;
2139         int res = 0;
2140
2141         for (srp = sfp->headrp; srp; srp = tsrp) {
2142                 tsrp = srp->nextrp;
2143                 if (sg_srp_done(srp, sfp))
2144                         sg_finish_rem_req(srp);
2145                 else
2146                         ++dirty;
2147         }
2148         if (0 == dirty) {
2149                 unsigned long iflags;
2150
2151                 write_lock_irqsave(&sg_index_lock, iflags);
2152                 __sg_remove_sfp(sdp, sfp);
2153                 if (sdp->detached && (NULL == sdp->headfp)) {
2154                         idr_remove(&sg_index_idr, sdp->index);
2155                         kfree(sdp);
2156                         res = 1;
2157                 }
2158                 write_unlock_irqrestore(&sg_index_lock, iflags);
2159         } else {
2160                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2161                 /* only bump the access_count if we actually succeeded in
2162                  * throwing another counter on the host module */
2163                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2164                 sfp->closed = 1;        /* flag dirty state on this fd */
2165                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2166                                   dirty));
2167         }
2168         return res;
2169 }
2170
2171 static int
2172 sg_res_in_use(Sg_fd * sfp)
2173 {
2174         const Sg_request *srp;
2175         unsigned long iflags;
2176
2177         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2178         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2179                 if (srp->res_used)
2180                         break;
2181         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2182         return srp ? 1 : 0;
2183 }
2184
2185 #ifdef CONFIG_SCSI_PROC_FS
2186 static int
2187 sg_idr_max_id(int id, void *p, void *data)
2188 {
2189         int *k = data;
2190
2191         if (*k < id)
2192                 *k = id;
2193
2194         return 0;
2195 }
2196
2197 static int
2198 sg_last_dev(void)
2199 {
2200         int k = -1;
2201         unsigned long iflags;
2202
2203         read_lock_irqsave(&sg_index_lock, iflags);
2204         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2205         read_unlock_irqrestore(&sg_index_lock, iflags);
2206         return k + 1;           /* origin 1 */
2207 }
2208 #endif
2209
2210 static Sg_device *
2211 sg_get_dev(int dev)
2212 {
2213         Sg_device *sdp;
2214         unsigned long iflags;
2215
2216         read_lock_irqsave(&sg_index_lock, iflags);
2217         sdp = idr_find(&sg_index_idr, dev);
2218         read_unlock_irqrestore(&sg_index_lock, iflags);
2219
2220         return sdp;
2221 }
2222
2223 #ifdef CONFIG_SCSI_PROC_FS
2224
2225 static struct proc_dir_entry *sg_proc_sgp = NULL;
2226
2227 static char sg_proc_sg_dirname[] = "scsi/sg";
2228
2229 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2230
2231 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2232 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2233                                   size_t count, loff_t *off);
2234 static struct file_operations adio_fops = {
2235         /* .owner, .read and .llseek added in sg_proc_init() */
2236         .open = sg_proc_single_open_adio,
2237         .write = sg_proc_write_adio,
2238         .release = single_release,
2239 };
2240
2241 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2242 static ssize_t sg_proc_write_dressz(struct file *filp,
2243                 const char __user *buffer, size_t count, loff_t *off);
2244 static struct file_operations dressz_fops = {
2245         .open = sg_proc_single_open_dressz,
2246         .write = sg_proc_write_dressz,
2247         .release = single_release,
2248 };
2249
2250 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2251 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2252 static struct file_operations version_fops = {
2253         .open = sg_proc_single_open_version,
2254         .release = single_release,
2255 };
2256
2257 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2258 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2259 static struct file_operations devhdr_fops = {
2260         .open = sg_proc_single_open_devhdr,
2261         .release = single_release,
2262 };
2263
2264 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2265 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2266 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2267 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2268 static void dev_seq_stop(struct seq_file *s, void *v);
2269 static struct file_operations dev_fops = {
2270         .open = sg_proc_open_dev,
2271         .release = seq_release,
2272 };
2273 static struct seq_operations dev_seq_ops = {
2274         .start = dev_seq_start,
2275         .next  = dev_seq_next,
2276         .stop  = dev_seq_stop,
2277         .show  = sg_proc_seq_show_dev,
2278 };
2279
2280 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2281 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2282 static struct file_operations devstrs_fops = {
2283         .open = sg_proc_open_devstrs,
2284         .release = seq_release,
2285 };
2286 static struct seq_operations devstrs_seq_ops = {
2287         .start = dev_seq_start,
2288         .next  = dev_seq_next,
2289         .stop  = dev_seq_stop,
2290         .show  = sg_proc_seq_show_devstrs,
2291 };
2292
2293 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2294 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2295 static struct file_operations debug_fops = {
2296         .open = sg_proc_open_debug,
2297         .release = seq_release,
2298 };
2299 static struct seq_operations debug_seq_ops = {
2300         .start = dev_seq_start,
2301         .next  = dev_seq_next,
2302         .stop  = dev_seq_stop,
2303         .show  = sg_proc_seq_show_debug,
2304 };
2305
2306
2307 struct sg_proc_leaf {
2308         const char * name;
2309         struct file_operations * fops;
2310 };
2311
2312 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2313         {"allow_dio", &adio_fops},
2314         {"debug", &debug_fops},
2315         {"def_reserved_size", &dressz_fops},
2316         {"device_hdr", &devhdr_fops},
2317         {"devices", &dev_fops},
2318         {"device_strs", &devstrs_fops},
2319         {"version", &version_fops}
2320 };
2321
2322 static int
2323 sg_proc_init(void)
2324 {
2325         int k, mask;
2326         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2327         struct sg_proc_leaf * leaf;
2328
2329         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2330         if (!sg_proc_sgp)
2331                 return 1;
2332         for (k = 0; k < num_leaves; ++k) {
2333                 leaf = &sg_proc_leaf_arr[k];
2334                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2335                 leaf->fops->owner = THIS_MODULE;
2336                 leaf->fops->read = seq_read;
2337                 leaf->fops->llseek = seq_lseek;
2338                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2339         }
2340         return 0;
2341 }
2342
2343 static void
2344 sg_proc_cleanup(void)
2345 {
2346         int k;
2347         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2348
2349         if (!sg_proc_sgp)
2350                 return;
2351         for (k = 0; k < num_leaves; ++k)
2352                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2353         remove_proc_entry(sg_proc_sg_dirname, NULL);
2354 }
2355
2356
2357 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2358 {
2359         seq_printf(s, "%d\n", *((int *)s->private));
2360         return 0;
2361 }
2362
2363 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2364 {
2365         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2366 }
2367
2368 static ssize_t
2369 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2370                    size_t count, loff_t *off)
2371 {
2372         int num;
2373         char buff[11];
2374
2375         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2376                 return -EACCES;
2377         num = (count < 10) ? count : 10;
2378         if (copy_from_user(buff, buffer, num))
2379                 return -EFAULT;
2380         buff[num] = '\0';
2381         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2382         return count;
2383 }
2384
2385 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2386 {
2387         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2388 }
2389
2390 static ssize_t
2391 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2392                      size_t count, loff_t *off)
2393 {
2394         int num;
2395         unsigned long k = ULONG_MAX;
2396         char buff[11];
2397
2398         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2399                 return -EACCES;
2400         num = (count < 10) ? count : 10;
2401         if (copy_from_user(buff, buffer, num))
2402                 return -EFAULT;
2403         buff[num] = '\0';
2404         k = simple_strtoul(buff, NULL, 10);
2405         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2406                 sg_big_buff = k;
2407                 return count;
2408         }
2409         return -ERANGE;
2410 }
2411
2412 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2413 {
2414         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2415                    sg_version_date);
2416         return 0;
2417 }
2418
2419 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2420 {
2421         return single_open(file, sg_proc_seq_show_version, NULL);
2422 }
2423
2424 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2425 {
2426         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2427                    "online\n");
2428         return 0;
2429 }
2430
2431 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2432 {
2433         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2434 }
2435
2436 struct sg_proc_deviter {
2437         loff_t  index;
2438         size_t  max;
2439 };
2440
2441 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2442 {
2443         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2444
2445         s->private = it;
2446         if (! it)
2447                 return NULL;
2448
2449         it->index = *pos;
2450         it->max = sg_last_dev();
2451         if (it->index >= it->max)
2452                 return NULL;
2453         return it;
2454 }
2455
2456 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2457 {
2458         struct sg_proc_deviter * it = s->private;
2459
2460         *pos = ++it->index;
2461         return (it->index < it->max) ? it : NULL;
2462 }
2463
2464 static void dev_seq_stop(struct seq_file *s, void *v)
2465 {
2466         kfree(s->private);
2467 }
2468
2469 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2470 {
2471         return seq_open(file, &dev_seq_ops);
2472 }
2473
2474 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2475 {
2476         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2477         Sg_device *sdp;
2478         struct scsi_device *scsidp;
2479
2480         sdp = it ? sg_get_dev(it->index) : NULL;
2481         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2482                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2483                               scsidp->host->host_no, scsidp->channel,
2484                               scsidp->id, scsidp->lun, (int) scsidp->type,
2485                               1,
2486                               (int) scsidp->queue_depth,
2487                               (int) scsidp->device_busy,
2488                               (int) scsi_device_online(scsidp));
2489         else
2490                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2491         return 0;
2492 }
2493
2494 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2495 {
2496         return seq_open(file, &devstrs_seq_ops);
2497 }
2498
2499 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2500 {
2501         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2502         Sg_device *sdp;
2503         struct scsi_device *scsidp;
2504
2505         sdp = it ? sg_get_dev(it->index) : NULL;
2506         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2507                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2508                            scsidp->vendor, scsidp->model, scsidp->rev);
2509         else
2510                 seq_printf(s, "<no active device>\n");
2511         return 0;
2512 }
2513
2514 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2515 {
2516         int k, m, new_interface, blen, usg;
2517         Sg_request *srp;
2518         Sg_fd *fp;
2519         const sg_io_hdr_t *hp;
2520         const char * cp;
2521         unsigned int ms;
2522
2523         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2524                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2525                            "(res)sgat=%d low_dma=%d\n", k + 1,
2526                            jiffies_to_msecs(fp->timeout),
2527                            fp->reserve.bufflen,
2528                            (int) fp->reserve.k_use_sg,
2529                            (int) fp->low_dma);
2530                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2531                            (int) fp->cmd_q, (int) fp->force_packid,
2532                            (int) fp->keep_orphan, (int) fp->closed);
2533                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2534                         hp = &srp->header;
2535                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2536                         if (srp->res_used) {
2537                                 if (new_interface &&
2538                                     (SG_FLAG_MMAP_IO & hp->flags))
2539                                         cp = "     mmap>> ";
2540                                 else
2541                                         cp = "     rb>> ";
2542                         } else {
2543                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2544                                         cp = "     dio>> ";
2545                                 else
2546                                         cp = "     ";
2547                         }
2548                         seq_printf(s, cp);
2549                         blen = srp->data.bufflen;
2550                         usg = srp->data.k_use_sg;
2551                         seq_printf(s, srp->done ?
2552                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2553                                    : "act:");
2554                         seq_printf(s, " id=%d blen=%d",
2555                                    srp->header.pack_id, blen);
2556                         if (srp->done)
2557                                 seq_printf(s, " dur=%d", hp->duration);
2558                         else {
2559                                 ms = jiffies_to_msecs(jiffies);
2560                                 seq_printf(s, " t_o/elap=%d/%d",
2561                                         (new_interface ? hp->timeout :
2562                                                   jiffies_to_msecs(fp->timeout)),
2563                                         (ms > hp->duration ? ms - hp->duration : 0));
2564                         }
2565                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2566                                    (int) srp->data.cmd_opcode);
2567                 }
2568                 if (0 == m)
2569                         seq_printf(s, "     No requests active\n");
2570         }
2571 }
2572
2573 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2574 {
2575         return seq_open(file, &debug_seq_ops);
2576 }
2577
2578 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2579 {
2580         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2581         Sg_device *sdp;
2582
2583         if (it && (0 == it->index)) {
2584                 seq_printf(s, "max_active_device=%d(origin 1)\n",
2585                            (int)it->max);
2586                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2587         }
2588         sdp = it ? sg_get_dev(it->index) : NULL;
2589         if (sdp) {
2590                 struct scsi_device *scsidp = sdp->device;
2591
2592                 if (NULL == scsidp) {
2593                         seq_printf(s, "device %d detached ??\n",
2594                                    (int)it->index);
2595                         return 0;
2596                 }
2597
2598                 if (sg_get_nth_sfp(sdp, 0)) {
2599                         seq_printf(s, " >>> device=%s ",
2600                                 sdp->disk->disk_name);
2601                         if (sdp->detached)
2602                                 seq_printf(s, "detached pending close ");
2603                         else
2604                                 seq_printf
2605                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2606                                      scsidp->host->host_no,
2607                                      scsidp->channel, scsidp->id,
2608                                      scsidp->lun,
2609                                      scsidp->host->hostt->emulated);
2610                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2611                                    sdp->sg_tablesize, sdp->exclude);
2612                 }
2613                 sg_proc_debug_helper(s, sdp);
2614         }
2615         return 0;
2616 }
2617
2618 #endif                          /* CONFIG_SCSI_PROC_FS */
2619
2620 module_init(init_sg);
2621 module_exit(exit_sg);