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 = 30533;      /* 2 digits for each component */
  22 #define SG_VERSION_STR "3.5.33"
  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/config.h>
  32 #include <linux/module.h>
  33
  34 #include <linux/fs.h>
  35 #include <linux/kernel.h>
  36 #include <linux/sched.h>
  37 #include <linux/string.h>
  38 #include <linux/mm.h>
  39 #include <linux/errno.h>
  40 #include <linux/mtio.h>
  41 #include <linux/ioctl.h>
  42 #include <linux/fcntl.h>
  43 #include <linux/init.h>
  44 #include <linux/poll.h>
  45 #include <linux/smp_lock.h>
  46 #include <linux/moduleparam.h>
  47 #include <linux/cdev.h>
  48 #include <linux/seq_file.h>
  49 #include <linux/blkdev.h>
  50 #include <linux/delay.h>
  51 #include <linux/scatterlist.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 = "20050908";
  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 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
  72
  73 #define SG_MAX_DEVS 32768
  74
  75 /*
  76  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  77  * Then when using 32 bit integers x * m may overflow during the calculation.
  78  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  79  * calculates the same, but prevents the overflow when both m and d
  80  * are "small" numbers (like HZ and USER_HZ).
  81  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  82  * in 32 bits.
  83  */
  84 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  85
  86 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  87
  88 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  89 /* N.B. This variable is readable and writeable via
  90    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  91    of this size (or less if there is not enough memory) will be reserved
  92    for use by this file descriptor. [Deprecated usage: this variable is also
  93    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  94    the kernel (i.e. it is not a module).] */
  95 static int def_reserved_size = -1;      /* picks up init parameter */
  96 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  97
  98 #define SG_SECTOR_SZ 512
  99 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 100
 101 #define SG_DEV_ARR_LUMP 32      /* amount to over allocate sg_dev_arr by */
 102
 103 static int sg_add(struct class_device *, struct class_interface *);
 104 static void sg_remove(struct class_device *, struct class_interface *);
 105
 106 static DEFINE_RWLOCK(sg_dev_arr_lock);  /* Also used to lock
 107                                                            file descriptor list for device */
 108
 109 static struct class_interface sg_interface = {
 110         .add            = sg_add,
 111         .remove         = sg_remove,
 112 };
 113
 114 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 115         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 116         unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
 117         unsigned bufflen;       /* Size of (aggregate) data buffer */
 118         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
 119         struct scatterlist *buffer;/* scatter list */
 120         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 121         unsigned char cmd_opcode; /* first byte of command */
 122 } Sg_scatter_hold;
 123
 124 struct sg_device;               /* forward declarations */
 125 struct sg_fd;
 126
 127 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 128         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 129         struct sg_fd *parentfp; /* NULL -> not in use */
 130         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 131         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 132         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 133         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 134         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 135         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 136         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 137 } Sg_request;
 138
 139 typedef struct sg_fd {          /* holds the state of a file descriptor */
 140         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 141         struct sg_device *parentdp;     /* owning device */
 142         wait_queue_head_t read_wait;    /* queue read until command done */
 143         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 144         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 145         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 146         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 147         unsigned save_scat_len; /* original length of trunc. scat. element */
 148         Sg_request *headrp;     /* head of request slist, NULL->empty */
 149         struct fasync_struct *async_qp; /* used by asynchronous notification */
 150         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 151         char low_dma;           /* as in parent but possibly overridden to 1 */
 152         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 153         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 154         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 155         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 156         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 157         char mmap_called;       /* 0 -> mmap() never called on this fd */
 158 } Sg_fd;
 159
 160 typedef struct sg_device { /* holds the state of each scsi generic device */
 161         struct scsi_device *device;
 162         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 163         int sg_tablesize;       /* adapter's max scatter-gather table size */
 164         Sg_fd *headfp;          /* first open fd belonging to this device */
 165         volatile char detached; /* 0->attached, 1->detached pending removal */
 166         volatile char exclude;  /* opened for exclusive access */
 167         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 168         struct gendisk *disk;
 169         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 170 } Sg_device;
 171
 172 static int sg_fasync(int fd, struct file *filp, int mode);
 173 /* tasklet or soft irq callback */
 174 static void sg_cmd_done(void *data, char *sense, int result, int resid);
 175 static int sg_start_req(Sg_request * srp);
 176 static void sg_finish_rem_req(Sg_request * srp);
 177 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 178 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
 179                          int tablesize);
 180 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 181                            Sg_request * srp);
 182 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 183                             int blocking, int read_only, Sg_request ** o_srp);
 184 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 185                            unsigned char *cmnd, int timeout, int blocking);
 186 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
 187                       int wr_xf, int *countp, unsigned char __user **up);
 188 static int sg_write_xfer(Sg_request * srp);
 189 static int sg_read_xfer(Sg_request * srp);
 190 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 191 static void sg_remove_scat(Sg_scatter_hold * schp);
 192 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 193 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 194 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 195 static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
 196 static void sg_page_free(struct page *page, int size);
 197 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 198 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 199 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 200 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 201 static Sg_request *sg_add_request(Sg_fd * sfp);
 202 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 203 static int sg_res_in_use(Sg_fd * sfp);
 204 static int sg_allow_access(unsigned char opcode, char dev_type);
 205 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
 206 static Sg_device *sg_get_dev(int dev);
 207 #ifdef CONFIG_SCSI_PROC_FS
 208 static int sg_last_dev(void);
 209 #endif
 210
 211 static Sg_device **sg_dev_arr = NULL;
 212 static int sg_dev_max;
 213 static int sg_nr_dev;
 214
 215 #define SZ_SG_HEADER sizeof(struct sg_header)
 216 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 217 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 218 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 219
 220 static int
 221 sg_open(struct inode *inode, struct file *filp)
 222 {
 223         int dev = iminor(inode);
 224         int flags = filp->f_flags;
 225         struct request_queue *q;
 226         Sg_device *sdp;
 227         Sg_fd *sfp;
 228         int res;
 229         int retval;
 230
 231         nonseekable_open(inode, filp);
 232         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 233         sdp = sg_get_dev(dev);
 234         if ((!sdp) || (!sdp->device))
 235                 return -ENXIO;
 236         if (sdp->detached)
 237                 return -ENODEV;
 238
 239         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 240         /* Prevent the device driver from vanishing while we sleep */
 241         retval = scsi_device_get(sdp->device);
 242         if (retval)
 243                 return retval;
 244
 245         if (!((flags & O_NONBLOCK) ||
 246               scsi_block_when_processing_errors(sdp->device))) {
 247                 retval = -ENXIO;
 248                 /* we are in error recovery for this device */
 249                 goto error_out;
 250         }
 251
 252         if (flags & O_EXCL) {
 253                 if (O_RDONLY == (flags & O_ACCMODE)) {
 254                         retval = -EPERM; /* Can't lock it with read only access */
 255                         goto error_out;
 256                 }
 257                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 258                         retval = -EBUSY;
 259                         goto error_out;
 260                 }
 261                 res = 0;
 262                 __wait_event_interruptible(sdp->o_excl_wait,
 263                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 264                 if (res) {
 265                         retval = res;   /* -ERESTARTSYS because signal hit process */
 266                         goto error_out;
 267                 }
 268         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 269                 if (flags & O_NONBLOCK) {
 270                         retval = -EBUSY;
 271                         goto error_out;
 272                 }
 273                 res = 0;
 274                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 275                                            res);
 276                 if (res) {
 277                         retval = res;   /* -ERESTARTSYS because signal hit process */
 278                         goto error_out;
 279                 }
 280         }
 281         if (sdp->detached) {
 282                 retval = -ENODEV;
 283                 goto error_out;
 284         }
 285         if (!sdp->headfp) {     /* no existing opens on this device */
 286                 sdp->sgdebug = 0;
 287                 q = sdp->device->request_queue;
 288                 sdp->sg_tablesize = min(q->max_hw_segments,
 289                                         q->max_phys_segments);
 290         }
 291         if ((sfp = sg_add_sfp(sdp, dev)))
 292                 filp->private_data = sfp;
 293         else {
 294                 if (flags & O_EXCL)
 295                         sdp->exclude = 0;       /* undo if error */
 296                 retval = -ENOMEM;
 297                 goto error_out;
 298         }
 299         return 0;
 300
 301       error_out:
 302         scsi_device_put(sdp->device);
 303         return retval;
 304 }
 305
 306 /* Following function was formerly called 'sg_close' */
 307 static int
 308 sg_release(struct inode *inode, struct file *filp)
 309 {
 310         Sg_device *sdp;
 311         Sg_fd *sfp;
 312
 313         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 314                 return -ENXIO;
 315         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 316         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 317         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 318                 if (!sdp->detached) {
 319                         scsi_device_put(sdp->device);
 320                 }
 321                 sdp->exclude = 0;
 322                 wake_up_interruptible(&sdp->o_excl_wait);
 323         }
 324         return 0;
 325 }
 326
 327 static ssize_t
 328 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 329 {
 330         Sg_device *sdp;
 331         Sg_fd *sfp;
 332         Sg_request *srp;
 333         int req_pack_id = -1;
 334         sg_io_hdr_t *hp;
 335         struct sg_header *old_hdr = NULL;
 336         int retval = 0;
 337
 338         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 339                 return -ENXIO;
 340         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 341                                    sdp->disk->disk_name, (int) count));
 342
 343         if (!access_ok(VERIFY_WRITE, buf, count))
 344                 return -EFAULT;
 345         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 346                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 347                 if (!old_hdr)
 348                         return -ENOMEM;
 349                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 350                         retval = -EFAULT;
 351                         goto free_old_hdr;
 352                 }
 353                 if (old_hdr->reply_len < 0) {
 354                         if (count >= SZ_SG_IO_HDR) {
 355                                 sg_io_hdr_t *new_hdr;
 356                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 357                                 if (!new_hdr) {
 358                                         retval = -ENOMEM;
 359                                         goto free_old_hdr;
 360                                 }
 361                                 retval =__copy_from_user
 362                                     (new_hdr, buf, SZ_SG_IO_HDR);
 363                                 req_pack_id = new_hdr->pack_id;
 364                                 kfree(new_hdr);
 365                                 if (retval) {
 366                                         retval = -EFAULT;
 367                                         goto free_old_hdr;
 368                                 }
 369                         }
 370                 } else
 371                         req_pack_id = old_hdr->pack_id;
 372         }
 373         srp = sg_get_rq_mark(sfp, req_pack_id);
 374         if (!srp) {             /* now wait on packet to arrive */
 375                 if (sdp->detached) {
 376                         retval = -ENODEV;
 377                         goto free_old_hdr;
 378                 }
 379                 if (filp->f_flags & O_NONBLOCK) {
 380                         retval = -EAGAIN;
 381                         goto free_old_hdr;
 382                 }
 383                 while (1) {
 384                         retval = 0; /* following macro beats race condition */
 385                         __wait_event_interruptible(sfp->read_wait,
 386                                 (sdp->detached ||
 387                                 (srp = sg_get_rq_mark(sfp, req_pack_id))),
 388                                 retval);
 389                         if (sdp->detached) {
 390                                 retval = -ENODEV;
 391                                 goto free_old_hdr;
 392                         }
 393                         if (0 == retval)
 394                                 break;
 395
 396                         /* -ERESTARTSYS as signal hit process */
 397                         goto free_old_hdr;
 398                 }
 399         }
 400         if (srp->header.interface_id != '\0') {
 401                 retval = sg_new_read(sfp, buf, count, srp);
 402                 goto free_old_hdr;
 403         }
 404
 405         hp = &srp->header;
 406         if (old_hdr == NULL) {
 407                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 408                 if (! old_hdr) {
 409                         retval = -ENOMEM;
 410                         goto free_old_hdr;
 411                 }
 412         }
 413         memset(old_hdr, 0, SZ_SG_HEADER);
 414         old_hdr->reply_len = (int) hp->timeout;
 415         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 416         old_hdr->pack_id = hp->pack_id;
 417         old_hdr->twelve_byte =
 418             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 419         old_hdr->target_status = hp->masked_status;
 420         old_hdr->host_status = hp->host_status;
 421         old_hdr->driver_status = hp->driver_status;
 422         if ((CHECK_CONDITION & hp->masked_status) ||
 423             (DRIVER_SENSE & hp->driver_status))
 424                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 425                        sizeof (old_hdr->sense_buffer));
 426         switch (hp->host_status) {
 427         /* This setup of 'result' is for backward compatibility and is best
 428            ignored by the user who should use target, host + driver status */
 429         case DID_OK:
 430         case DID_PASSTHROUGH:
 431         case DID_SOFT_ERROR:
 432                 old_hdr->result = 0;
 433                 break;
 434         case DID_NO_CONNECT:
 435         case DID_BUS_BUSY:
 436         case DID_TIME_OUT:
 437                 old_hdr->result = EBUSY;
 438                 break;
 439         case DID_BAD_TARGET:
 440         case DID_ABORT:
 441         case DID_PARITY:
 442         case DID_RESET:
 443         case DID_BAD_INTR:
 444                 old_hdr->result = EIO;
 445                 break;
 446         case DID_ERROR:
 447                 old_hdr->result = (srp->sense_b[0] == 0 &&
 448                                   hp->masked_status == GOOD) ? 0 : EIO;
 449                 break;
 450         default:
 451                 old_hdr->result = EIO;
 452                 break;
 453         }
 454
 455         /* Now copy the result back to the user buffer.  */
 456         if (count >= SZ_SG_HEADER) {
 457                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 458                         retval = -EFAULT;
 459                         goto free_old_hdr;
 460                 }
 461                 buf += SZ_SG_HEADER;
 462                 if (count > old_hdr->reply_len)
 463                         count = old_hdr->reply_len;
 464                 if (count > SZ_SG_HEADER) {
 465                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 466                                 retval = -EFAULT;
 467                                 goto free_old_hdr;
 468                         }
 469                 }
 470         } else
 471                 count = (old_hdr->result == 0) ? 0 : -EIO;
 472         sg_finish_rem_req(srp);
 473         retval = count;
 474 free_old_hdr:
 475         kfree(old_hdr);
 476         return retval;
 477 }
 478
 479 static ssize_t
 480 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 481 {
 482         sg_io_hdr_t *hp = &srp->header;
 483         int err = 0;
 484         int len;
 485
 486         if (count < SZ_SG_IO_HDR) {
 487                 err = -EINVAL;
 488                 goto err_out;
 489         }
 490         hp->sb_len_wr = 0;
 491         if ((hp->mx_sb_len > 0) && hp->sbp) {
 492                 if ((CHECK_CONDITION & hp->masked_status) ||
 493                     (DRIVER_SENSE & hp->driver_status)) {
 494                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 495                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 496                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 497                         len = (len > sb_len) ? sb_len : len;
 498                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 499                                 err = -EFAULT;
 500                                 goto err_out;
 501                         }
 502                         hp->sb_len_wr = len;
 503                 }
 504         }
 505         if (hp->masked_status || hp->host_status || hp->driver_status)
 506                 hp->info |= SG_INFO_CHECK;
 507         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 508                 err = -EFAULT;
 509                 goto err_out;
 510         }
 511         err = sg_read_xfer(srp);
 512       err_out:
 513         sg_finish_rem_req(srp);
 514         return (0 == err) ? count : err;
 515 }
 516
 517 static ssize_t
 518 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 519 {
 520         int mxsize, cmd_size, k;
 521         int input_size, blocking;
 522         unsigned char opcode;
 523         Sg_device *sdp;
 524         Sg_fd *sfp;
 525         Sg_request *srp;
 526         struct sg_header old_hdr;
 527         sg_io_hdr_t *hp;
 528         unsigned char cmnd[MAX_COMMAND_SIZE];
 529
 530         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 531                 return -ENXIO;
 532         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 533                                    sdp->disk->disk_name, (int) count));
 534         if (sdp->detached)
 535                 return -ENODEV;
 536         if (!((filp->f_flags & O_NONBLOCK) ||
 537               scsi_block_when_processing_errors(sdp->device)))
 538                 return -ENXIO;
 539
 540         if (!access_ok(VERIFY_READ, buf, count))
 541                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 542         if (count < SZ_SG_HEADER)
 543                 return -EIO;
 544         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 545                 return -EFAULT;
 546         blocking = !(filp->f_flags & O_NONBLOCK);
 547         if (old_hdr.reply_len < 0)
 548                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
 549         if (count < (SZ_SG_HEADER + 6))
 550                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 551
 552         if (!(srp = sg_add_request(sfp))) {
 553                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 554                 return -EDOM;
 555         }
 556         buf += SZ_SG_HEADER;
 557         __get_user(opcode, buf);
 558         if (sfp->next_cmd_len > 0) {
 559                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 560                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 561                         sfp->next_cmd_len = 0;
 562                         sg_remove_request(sfp, srp);
 563                         return -EIO;
 564                 }
 565                 cmd_size = sfp->next_cmd_len;
 566                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 567         } else {
 568                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 569                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 570                         cmd_size = 12;
 571         }
 572         SCSI_LOG_TIMEOUT(4, printk(
 573                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 574 /* Determine buffer size.  */
 575         input_size = count - cmd_size;
 576         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 577         mxsize -= SZ_SG_HEADER;
 578         input_size -= SZ_SG_HEADER;
 579         if (input_size < 0) {
 580                 sg_remove_request(sfp, srp);
 581                 return -EIO;    /* User did not pass enough bytes for this command. */
 582         }
 583         hp = &srp->header;
 584         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 585         hp->cmd_len = (unsigned char) cmd_size;
 586         hp->iovec_count = 0;
 587         hp->mx_sb_len = 0;
 588         if (input_size > 0)
 589                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 590                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 591         else
 592                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 593         hp->dxfer_len = mxsize;
 594         hp->dxferp = (char __user *)buf + cmd_size;
 595         hp->sbp = NULL;
 596         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 597         hp->flags = input_size; /* structure abuse ... */
 598         hp->pack_id = old_hdr.pack_id;
 599         hp->usr_ptr = NULL;
 600         if (__copy_from_user(cmnd, buf, cmd_size))
 601                 return -EFAULT;
 602         /*
 603          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 604          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 605          * is a non-zero input_size, so emit a warning.
 606          */
 607         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
 608                 if (printk_ratelimit())
 609                         printk(KERN_WARNING
 610                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 611                                "guessing data in;\n" KERN_WARNING "   "
 612                                "program %s not setting count and/or reply_len properly\n",
 613                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 614                                input_size, (unsigned int) cmnd[0],
 615                                current->comm);
 616         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 617         return (k < 0) ? k : count;
 618 }
 619
 620 static ssize_t
 621 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 622              int blocking, int read_only, Sg_request ** o_srp)
 623 {
 624         int k;
 625         Sg_request *srp;
 626         sg_io_hdr_t *hp;
 627         unsigned char cmnd[MAX_COMMAND_SIZE];
 628         int timeout;
 629         unsigned long ul_timeout;
 630
 631         if (count < SZ_SG_IO_HDR)
 632                 return -EINVAL;
 633         if (!access_ok(VERIFY_READ, buf, count))
 634                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 635
 636         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 637         if (!(srp = sg_add_request(sfp))) {
 638                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 639                 return -EDOM;
 640         }
 641         hp = &srp->header;
 642         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 643                 sg_remove_request(sfp, srp);
 644                 return -EFAULT;
 645         }
 646         if (hp->interface_id != 'S') {
 647                 sg_remove_request(sfp, srp);
 648                 return -ENOSYS;
 649         }
 650         if (hp->flags & SG_FLAG_MMAP_IO) {
 651                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 652                         sg_remove_request(sfp, srp);
 653                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 654                 }
 655                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 656                         sg_remove_request(sfp, srp);
 657                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 658                 }
 659                 if (sg_res_in_use(sfp)) {
 660                         sg_remove_request(sfp, srp);
 661                         return -EBUSY;  /* reserve buffer already being used */
 662                 }
 663         }
 664         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 665         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 666         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 667                 sg_remove_request(sfp, srp);
 668                 return -EMSGSIZE;
 669         }
 670         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 671                 sg_remove_request(sfp, srp);
 672                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 673         }
 674         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 675                 sg_remove_request(sfp, srp);
 676                 return -EFAULT;
 677         }
 678         if (read_only &&
 679             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
 680                 sg_remove_request(sfp, srp);
 681                 return -EPERM;
 682         }
 683         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 684         if (k < 0)
 685                 return k;
 686         if (o_srp)
 687                 *o_srp = srp;
 688         return count;
 689 }
 690
 691 static int
 692 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 693                 unsigned char *cmnd, int timeout, int blocking)
 694 {
 695         int k, data_dir;
 696         Sg_device *sdp = sfp->parentdp;
 697         sg_io_hdr_t *hp = &srp->header;
 698
 699         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 700         hp->status = 0;
 701         hp->masked_status = 0;
 702         hp->msg_status = 0;
 703         hp->info = 0;
 704         hp->host_status = 0;
 705         hp->driver_status = 0;
 706         hp->resid = 0;
 707         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 708                           (int) cmnd[0], (int) hp->cmd_len));
 709
 710         if ((k = sg_start_req(srp))) {
 711                 SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
 712                 sg_finish_rem_req(srp);
 713                 return k;       /* probably out of space --> ENOMEM */
 714         }
 715         if ((k = sg_write_xfer(srp))) {
 716                 SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
 717                 sg_finish_rem_req(srp);
 718                 return k;
 719         }
 720         if (sdp->detached) {
 721                 sg_finish_rem_req(srp);
 722                 return -ENODEV;
 723         }
 724
 725         switch (hp->dxfer_direction) {
 726         case SG_DXFER_TO_FROM_DEV:
 727         case SG_DXFER_FROM_DEV:
 728                 data_dir = DMA_FROM_DEVICE;
 729                 break;
 730         case SG_DXFER_TO_DEV:
 731                 data_dir = DMA_TO_DEVICE;
 732                 break;
 733         case SG_DXFER_UNKNOWN:
 734                 data_dir = DMA_BIDIRECTIONAL;
 735                 break;
 736         default:
 737                 data_dir = DMA_NONE;
 738                 break;
 739         }
 740         hp->duration = jiffies_to_msecs(jiffies);
 741 /* Now send everything of to mid-level. The next time we hear about this
 742    packet is when sg_cmd_done() is called (i.e. a callback). */
 743         if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
 744                                 hp->dxfer_len, srp->data.k_use_sg, timeout,
 745                                 SG_DEFAULT_RETRIES, srp, sg_cmd_done,
 746                                 GFP_ATOMIC)) {
 747                 SCSI_LOG_TIMEOUT(1, printk("sg_write: scsi_execute_async failed\n"));
 748                 /*
 749                  * most likely out of mem, but could also be a bad map
 750                  */
 751                 sg_finish_rem_req(srp);
 752                 return -ENOMEM;
 753         } else
 754                 return 0;
 755 }
 756
 757 static int
 758 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 759 {
 760         unsigned long iflags;
 761         int done;
 762
 763         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 764         done = srp->done;
 765         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 766         return done;
 767 }
 768
 769 static int
 770 sg_ioctl(struct inode *inode, struct file *filp,
 771          unsigned int cmd_in, unsigned long arg)
 772 {
 773         void __user *p = (void __user *)arg;
 774         int __user *ip = p;
 775         int result, val, read_only;
 776         Sg_device *sdp;
 777         Sg_fd *sfp;
 778         Sg_request *srp;
 779         unsigned long iflags;
 780
 781         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 782                 return -ENXIO;
 783         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 784                                    sdp->disk->disk_name, (int) cmd_in));
 785         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 786
 787         switch (cmd_in) {
 788         case SG_IO:
 789                 {
 790                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 791
 792                         if (sdp->detached)
 793                                 return -ENODEV;
 794                         if (!scsi_block_when_processing_errors(sdp->device))
 795                                 return -ENXIO;
 796                         if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 797                                 return -EFAULT;
 798                         result =
 799                             sg_new_write(sfp, p, SZ_SG_IO_HDR,
 800                                          blocking, read_only, &srp);
 801                         if (result < 0)
 802                                 return result;
 803                         srp->sg_io_owned = 1;
 804                         while (1) {
 805                                 result = 0;     /* following macro to beat race condition */
 806                                 __wait_event_interruptible(sfp->read_wait,
 807                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 808                                                            result);
 809                                 if (sdp->detached)
 810                                         return -ENODEV;
 811                                 if (sfp->closed)
 812                                         return 0;       /* request packet dropped already */
 813                                 if (0 == result)
 814                                         break;
 815                                 srp->orphan = 1;
 816                                 return result;  /* -ERESTARTSYS because signal hit process */
 817                         }
 818                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 819                         srp->done = 2;
 820                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 821                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 822                         return (result < 0) ? result : 0;
 823                 }
 824         case SG_SET_TIMEOUT:
 825                 result = get_user(val, ip);
 826                 if (result)
 827                         return result;
 828                 if (val < 0)
 829                         return -EIO;
 830                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 831                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 832                 sfp->timeout_user = val;
 833                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 834
 835                 return 0;
 836         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 837                                 /* strange ..., for backward compatibility */
 838                 return sfp->timeout_user;
 839         case SG_SET_FORCE_LOW_DMA:
 840                 result = get_user(val, ip);
 841                 if (result)
 842                         return result;
 843                 if (val) {
 844                         sfp->low_dma = 1;
 845                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 846                                 val = (int) sfp->reserve.bufflen;
 847                                 sg_remove_scat(&sfp->reserve);
 848                                 sg_build_reserve(sfp, val);
 849                         }
 850                 } else {
 851                         if (sdp->detached)
 852                                 return -ENODEV;
 853                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 854                 }
 855                 return 0;
 856         case SG_GET_LOW_DMA:
 857                 return put_user((int) sfp->low_dma, ip);
 858         case SG_GET_SCSI_ID:
 859                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 860                         return -EFAULT;
 861                 else {
 862                         sg_scsi_id_t __user *sg_idp = p;
 863
 864                         if (sdp->detached)
 865                                 return -ENODEV;
 866                         __put_user((int) sdp->device->host->host_no,
 867                                    &sg_idp->host_no);
 868                         __put_user((int) sdp->device->channel,
 869                                    &sg_idp->channel);
 870                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 871                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 872                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 873                         __put_user((short) sdp->device->host->cmd_per_lun,
 874                                    &sg_idp->h_cmd_per_lun);
 875                         __put_user((short) sdp->device->queue_depth,
 876                                    &sg_idp->d_queue_depth);
 877                         __put_user(0, &sg_idp->unused[0]);
 878                         __put_user(0, &sg_idp->unused[1]);
 879                         return 0;
 880                 }
 881         case SG_SET_FORCE_PACK_ID:
 882                 result = get_user(val, ip);
 883                 if (result)
 884                         return result;
 885                 sfp->force_packid = val ? 1 : 0;
 886                 return 0;
 887         case SG_GET_PACK_ID:
 888                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 889                         return -EFAULT;
 890                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 891                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 892                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 893                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 894                                                        iflags);
 895                                 __put_user(srp->header.pack_id, ip);
 896                                 return 0;
 897                         }
 898                 }
 899                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 900                 __put_user(-1, ip);
 901                 return 0;
 902         case SG_GET_NUM_WAITING:
 903                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 904                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 905                         if ((1 == srp->done) && (!srp->sg_io_owned))
 906                                 ++val;
 907                 }
 908                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 909                 return put_user(val, ip);
 910         case SG_GET_SG_TABLESIZE:
 911                 return put_user(sdp->sg_tablesize, ip);
 912         case SG_SET_RESERVED_SIZE:
 913                 result = get_user(val, ip);
 914                 if (result)
 915                         return result;
 916                 if (val < 0)
 917                         return -EINVAL;
 918                 if (val != sfp->reserve.bufflen) {
 919                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 920                                 return -EBUSY;
 921                         sg_remove_scat(&sfp->reserve);
 922                         sg_build_reserve(sfp, val);
 923                 }
 924                 return 0;
 925         case SG_GET_RESERVED_SIZE:
 926                 val = (int) sfp->reserve.bufflen;
 927                 return put_user(val, ip);
 928         case SG_SET_COMMAND_Q:
 929                 result = get_user(val, ip);
 930                 if (result)
 931                         return result;
 932                 sfp->cmd_q = val ? 1 : 0;
 933                 return 0;
 934         case SG_GET_COMMAND_Q:
 935                 return put_user((int) sfp->cmd_q, ip);
 936         case SG_SET_KEEP_ORPHAN:
 937                 result = get_user(val, ip);
 938                 if (result)
 939                         return result;
 940                 sfp->keep_orphan = val;
 941                 return 0;
 942         case SG_GET_KEEP_ORPHAN:
 943                 return put_user((int) sfp->keep_orphan, ip);
 944         case SG_NEXT_CMD_LEN:
 945                 result = get_user(val, ip);
 946                 if (result)
 947                         return result;
 948                 sfp->next_cmd_len = (val > 0) ? val : 0;
 949                 return 0;
 950         case SG_GET_VERSION_NUM:
 951                 return put_user(sg_version_num, ip);
 952         case SG_GET_ACCESS_COUNT:
 953                 /* faked - we don't have a real access count anymore */
 954                 val = (sdp->device ? 1 : 0);
 955                 return put_user(val, ip);
 956         case SG_GET_REQUEST_TABLE:
 957                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
 958                         return -EFAULT;
 959                 else {
 960                         sg_req_info_t *rinfo;
 961                         unsigned int ms;
 962
 963                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
 964                                                                 GFP_KERNEL);
 965                         if (!rinfo)
 966                                 return -ENOMEM;
 967                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 968                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 969                              ++val, srp = srp ? srp->nextrp : srp) {
 970                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 971                                 if (srp) {
 972                                         rinfo[val].req_state = srp->done + 1;
 973                                         rinfo[val].problem =
 974                                             srp->header.masked_status &
 975                                             srp->header.host_status &
 976                                             srp->header.driver_status;
 977                                         if (srp->done)
 978                                                 rinfo[val].duration =
 979                                                         srp->header.duration;
 980                                         else {
 981                                                 ms = jiffies_to_msecs(jiffies);
 982                                                 rinfo[val].duration =
 983                                                     (ms > srp->header.duration) ?
 984                                                     (ms - srp->header.duration) : 0;
 985                                         }
 986                                         rinfo[val].orphan = srp->orphan;
 987                                         rinfo[val].sg_io_owned =
 988                                                         srp->sg_io_owned;
 989                                         rinfo[val].pack_id =
 990                                                         srp->header.pack_id;
 991                                         rinfo[val].usr_ptr =
 992                                                         srp->header.usr_ptr;
 993                                 }
 994                         }
 995                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 996                         result = __copy_to_user(p, rinfo,
 997                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
 998                         result = result ? -EFAULT : 0;
 999                         kfree(rinfo);
1000                         return result;
1001                 }
1002         case SG_EMULATED_HOST:
1003                 if (sdp->detached)
1004                         return -ENODEV;
1005                 return put_user(sdp->device->host->hostt->emulated, ip);
1006         case SG_SCSI_RESET:
1007                 if (sdp->detached)
1008                         return -ENODEV;
1009                 if (filp->f_flags & O_NONBLOCK) {
1010                         if (scsi_host_in_recovery(sdp->device->host))
1011                                 return -EBUSY;
1012                 } else if (!scsi_block_when_processing_errors(sdp->device))
1013                         return -EBUSY;
1014                 result = get_user(val, ip);
1015                 if (result)
1016                         return result;
1017                 if (SG_SCSI_RESET_NOTHING == val)
1018                         return 0;
1019                 switch (val) {
1020                 case SG_SCSI_RESET_DEVICE:
1021                         val = SCSI_TRY_RESET_DEVICE;
1022                         break;
1023                 case SG_SCSI_RESET_BUS:
1024                         val = SCSI_TRY_RESET_BUS;
1025                         break;
1026                 case SG_SCSI_RESET_HOST:
1027                         val = SCSI_TRY_RESET_HOST;
1028                         break;
1029                 default:
1030                         return -EINVAL;
1031                 }
1032                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1033                         return -EACCES;
1034                 return (scsi_reset_provider(sdp->device, val) ==
1035                         SUCCESS) ? 0 : -EIO;
1036         case SCSI_IOCTL_SEND_COMMAND:
1037                 if (sdp->detached)
1038                         return -ENODEV;
1039                 if (read_only) {
1040                         unsigned char opcode = WRITE_6;
1041                         Scsi_Ioctl_Command __user *siocp = p;
1042
1043                         if (copy_from_user(&opcode, siocp->data, 1))
1044                                 return -EFAULT;
1045                         if (!sg_allow_access(opcode, sdp->device->type))
1046                                 return -EPERM;
1047                 }
1048                 return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1049         case SG_SET_DEBUG:
1050                 result = get_user(val, ip);
1051                 if (result)
1052                         return result;
1053                 sdp->sgdebug = (char) val;
1054                 return 0;
1055         case SCSI_IOCTL_GET_IDLUN:
1056         case SCSI_IOCTL_GET_BUS_NUMBER:
1057         case SCSI_IOCTL_PROBE_HOST:
1058         case SG_GET_TRANSFORM:
1059                 if (sdp->detached)
1060                         return -ENODEV;
1061                 return scsi_ioctl(sdp->device, cmd_in, p);
1062         default:
1063                 if (read_only)
1064                         return -EPERM;  /* don't know so take safe approach */
1065                 return scsi_ioctl(sdp->device, cmd_in, p);
1066         }
1067 }
1068
1069 #ifdef CONFIG_COMPAT
1070 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1071 {
1072         Sg_device *sdp;
1073         Sg_fd *sfp;
1074         struct scsi_device *sdev;
1075
1076         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1077                 return -ENXIO;
1078
1079         sdev = sdp->device;
1080         if (sdev->host->hostt->compat_ioctl) {
1081                 int ret;
1082
1083                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1084
1085                 return ret;
1086         }
1087
1088         return -ENOIOCTLCMD;
1089 }
1090 #endif
1091
1092 static unsigned int
1093 sg_poll(struct file *filp, poll_table * wait)
1094 {
1095         unsigned int res = 0;
1096         Sg_device *sdp;
1097         Sg_fd *sfp;
1098         Sg_request *srp;
1099         int count = 0;
1100         unsigned long iflags;
1101
1102         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1103             || sfp->closed)
1104                 return POLLERR;
1105         poll_wait(filp, &sfp->read_wait, wait);
1106         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1107         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1108                 /* if any read waiting, flag it */
1109                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1110                         res = POLLIN | POLLRDNORM;
1111                 ++count;
1112         }
1113         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1114
1115         if (sdp->detached)
1116                 res |= POLLHUP;
1117         else if (!sfp->cmd_q) {
1118                 if (0 == count)
1119                         res |= POLLOUT | POLLWRNORM;
1120         } else if (count < SG_MAX_QUEUE)
1121                 res |= POLLOUT | POLLWRNORM;
1122         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1123                                    sdp->disk->disk_name, (int) res));
1124         return res;
1125 }
1126
1127 static int
1128 sg_fasync(int fd, struct file *filp, int mode)
1129 {
1130         int retval;
1131         Sg_device *sdp;
1132         Sg_fd *sfp;
1133
1134         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1135                 return -ENXIO;
1136         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1137                                    sdp->disk->disk_name, mode));
1138
1139         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1140         return (retval < 0) ? retval : 0;
1141 }
1142
1143 static struct page *
1144 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1145 {
1146         Sg_fd *sfp;
1147         struct page *page = NOPAGE_SIGBUS;
1148         unsigned long offset, len, sa;
1149         Sg_scatter_hold *rsv_schp;
1150         struct scatterlist *sg;
1151         int k;
1152
1153         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1154                 return page;
1155         rsv_schp = &sfp->reserve;
1156         offset = addr - vma->vm_start;
1157         if (offset >= rsv_schp->bufflen)
1158                 return page;
1159         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1160                                    offset, rsv_schp->k_use_sg));
1161         sg = rsv_schp->buffer;
1162         sa = vma->vm_start;
1163         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1164              ++k, ++sg) {
1165                 len = vma->vm_end - sa;
1166                 len = (len < sg->length) ? len : sg->length;
1167                 if (offset < len) {
1168                         page = sg->page;
1169                         get_page(page); /* increment page count */
1170                         break;
1171                 }
1172                 sa += len;
1173                 offset -= len;
1174         }
1175
1176         if (type)
1177                 *type = VM_FAULT_MINOR;
1178         return page;
1179 }
1180
1181 static struct vm_operations_struct sg_mmap_vm_ops = {
1182         .nopage = sg_vma_nopage,
1183 };
1184
1185 static int
1186 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1187 {
1188         Sg_fd *sfp;
1189         unsigned long req_sz, len, sa;
1190         Sg_scatter_hold *rsv_schp;
1191         int k;
1192         struct scatterlist *sg;
1193
1194         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1195                 return -ENXIO;
1196         req_sz = vma->vm_end - vma->vm_start;
1197         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1198                                    (void *) vma->vm_start, (int) req_sz));
1199         if (vma->vm_pgoff)
1200                 return -EINVAL; /* want no offset */
1201         rsv_schp = &sfp->reserve;
1202         if (req_sz > rsv_schp->bufflen)
1203                 return -ENOMEM; /* cannot map more than reserved buffer */
1204
1205         sa = vma->vm_start;
1206         sg = rsv_schp->buffer;
1207         for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1208              ++k, ++sg) {
1209                 len = vma->vm_end - sa;
1210                 len = (len < sg->length) ? len : sg->length;
1211                 sa += len;
1212         }
1213
1214         sfp->mmap_called = 1;
1215         vma->vm_flags |= VM_RESERVED;
1216         vma->vm_private_data = sfp;
1217         vma->vm_ops = &sg_mmap_vm_ops;
1218         return 0;
1219 }
1220
1221 /* This function is a "bottom half" handler that is called by the
1222  * mid level when a command is completed (or has failed). */
1223 static void
1224 sg_cmd_done(void *data, char *sense, int result, int resid)
1225 {
1226         Sg_request *srp = data;
1227         Sg_device *sdp = NULL;
1228         Sg_fd *sfp;
1229         unsigned long iflags;
1230         unsigned int ms;
1231
1232         if (NULL == srp) {
1233                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1234                 return;
1235         }
1236         sfp = srp->parentfp;
1237         if (sfp)
1238                 sdp = sfp->parentdp;
1239         if ((NULL == sdp) || sdp->detached) {
1240                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1241                 return;
1242         }
1243
1244
1245         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1246                 sdp->disk->disk_name, srp->header.pack_id, result));
1247         srp->header.resid = resid;
1248         ms = jiffies_to_msecs(jiffies);
1249         srp->header.duration = (ms > srp->header.duration) ?
1250                                 (ms - srp->header.duration) : 0;
1251         if (0 != result) {
1252                 struct scsi_sense_hdr sshdr;
1253
1254                 memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
1255                 srp->header.status = 0xff & result;
1256                 srp->header.masked_status = status_byte(result);
1257                 srp->header.msg_status = msg_byte(result);
1258                 srp->header.host_status = host_byte(result);
1259                 srp->header.driver_status = driver_byte(result);
1260                 if ((sdp->sgdebug > 0) &&
1261                     ((CHECK_CONDITION == srp->header.masked_status) ||
1262                      (COMMAND_TERMINATED == srp->header.masked_status)))
1263                         __scsi_print_sense("sg_cmd_done", sense,
1264                                            SCSI_SENSE_BUFFERSIZE);
1265
1266                 /* Following if statement is a patch supplied by Eric Youngdale */
1267                 if (driver_byte(result) != 0
1268                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1269                     && !scsi_sense_is_deferred(&sshdr)
1270                     && sshdr.sense_key == UNIT_ATTENTION
1271                     && sdp->device->removable) {
1272                         /* Detected possible disc change. Set the bit - this */
1273                         /* may be used if there are filesystems using this device */
1274                         sdp->device->changed = 1;
1275                 }
1276         }
1277         /* Rely on write phase to clean out srp status values, so no "else" */
1278
1279         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1280                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1281                 sg_finish_rem_req(srp);
1282                 srp = NULL;
1283                 if (NULL == sfp->headrp) {
1284                         SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1285                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1286                                 scsi_device_put(sdp->device);
1287                         }
1288                         sfp = NULL;
1289                 }
1290         } else if (srp && srp->orphan) {
1291                 if (sfp->keep_orphan)
1292                         srp->sg_io_owned = 0;
1293                 else {
1294                         sg_finish_rem_req(srp);
1295                         srp = NULL;
1296                 }
1297         }
1298         if (sfp && srp) {
1299                 /* Now wake up any sg_read() that is waiting for this packet. */
1300                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1301                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1302                 srp->done = 1;
1303                 wake_up_interruptible(&sfp->read_wait);
1304                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1305         }
1306 }
1307
1308 static struct file_operations sg_fops = {
1309         .owner = THIS_MODULE,
1310         .read = sg_read,
1311         .write = sg_write,
1312         .poll = sg_poll,
1313         .ioctl = sg_ioctl,
1314 #ifdef CONFIG_COMPAT
1315         .compat_ioctl = sg_compat_ioctl,
1316 #endif
1317         .open = sg_open,
1318         .mmap = sg_mmap,
1319         .release = sg_release,
1320         .fasync = sg_fasync,
1321 };
1322
1323 static struct class *sg_sysfs_class;
1324
1325 static int sg_sysfs_valid = 0;
1326
1327 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1328 {
1329         struct request_queue *q = scsidp->request_queue;
1330         Sg_device *sdp;
1331         unsigned long iflags;
1332         void *old_sg_dev_arr = NULL;
1333         int k, error;
1334
1335         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1336         if (!sdp) {
1337                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1338                 return -ENOMEM;
1339         }
1340
1341         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1342         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1343                 Sg_device **tmp_da;
1344                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1345                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1346
1347                 tmp_da = kzalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1348                 if (unlikely(!tmp_da))
1349                         goto expand_failed;
1350
1351                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1352                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1353                 old_sg_dev_arr = sg_dev_arr;
1354                 sg_dev_arr = tmp_da;
1355                 sg_dev_max = tmp_dev_max;
1356         }
1357
1358         for (k = 0; k < sg_dev_max; k++)
1359                 if (!sg_dev_arr[k])
1360                         break;
1361         if (unlikely(k >= SG_MAX_DEVS))
1362                 goto overflow;
1363
1364         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1365         sprintf(disk->disk_name, "sg%d", k);
1366         disk->first_minor = k;
1367         sdp->disk = disk;
1368         sdp->device = scsidp;
1369         init_waitqueue_head(&sdp->o_excl_wait);
1370         sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1371
1372         sg_nr_dev++;
1373         sg_dev_arr[k] = sdp;
1374         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1375         error = k;
1376
1377  out:
1378         if (error < 0)
1379                 kfree(sdp);
1380         kfree(old_sg_dev_arr);
1381         return error;
1382
1383  expand_failed:
1384         printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1385         error = -ENOMEM;
1386         goto out;
1387
1388  overflow:
1389         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1390         sdev_printk(KERN_WARNING, scsidp,
1391                     "Unable to attach sg device type=%d, minor "
1392                     "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1393         error = -ENODEV;
1394         goto out;
1395 }
1396
1397 static int
1398 sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
1399 {
1400         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1401         struct gendisk *disk;
1402         Sg_device *sdp = NULL;
1403         struct cdev * cdev = NULL;
1404         int error, k;
1405         unsigned long iflags;
1406
1407         disk = alloc_disk(1);
1408         if (!disk) {
1409                 printk(KERN_WARNING "alloc_disk failed\n");
1410                 return -ENOMEM;
1411         }
1412         disk->major = SCSI_GENERIC_MAJOR;
1413
1414         error = -ENOMEM;
1415         cdev = cdev_alloc();
1416         if (!cdev) {
1417                 printk(KERN_WARNING "cdev_alloc failed\n");
1418                 goto out;
1419         }
1420         cdev->owner = THIS_MODULE;
1421         cdev->ops = &sg_fops;
1422
1423         error = sg_alloc(disk, scsidp);
1424         if (error < 0) {
1425                 printk(KERN_WARNING "sg_alloc failed\n");
1426                 goto out;
1427         }
1428         k = error;
1429         sdp = sg_dev_arr[k];
1430
1431         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1432         if (error)
1433                 goto cdev_add_err;
1434
1435         sdp->cdev = cdev;
1436         if (sg_sysfs_valid) {
1437                 struct class_device * sg_class_member;
1438
1439                 sg_class_member = class_device_create(sg_sysfs_class, NULL,
1440                                 MKDEV(SCSI_GENERIC_MAJOR, k),
1441                                 cl_dev->dev, "%s",
1442                                 disk->disk_name);
1443                 if (IS_ERR(sg_class_member))
1444                         printk(KERN_WARNING "sg_add: "
1445                                 "class_device_create failed\n");
1446                 class_set_devdata(sg_class_member, sdp);
1447                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1448                                           &sg_class_member->kobj, "generic");
1449                 if (error)
1450                         printk(KERN_ERR "sg_add: unable to make symlink "
1451                                         "'generic' back to sg%d\n", k);
1452         } else
1453                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1454
1455         sdev_printk(KERN_NOTICE, scsidp,
1456                     "Attached scsi generic sg%d type %d\n", k,scsidp->type);
1457
1458         return 0;
1459
1460 cdev_add_err:
1461         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1462         kfree(sg_dev_arr[k]);
1463         sg_dev_arr[k] = NULL;
1464         sg_nr_dev--;
1465         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1466
1467 out:
1468         put_disk(disk);
1469         if (cdev)
1470                 cdev_del(cdev);
1471         return error;
1472 }
1473
1474 static void
1475 sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
1476 {
1477         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1478         Sg_device *sdp = NULL;
1479         unsigned long iflags;
1480         Sg_fd *sfp;
1481         Sg_fd *tsfp;
1482         Sg_request *srp;
1483         Sg_request *tsrp;
1484         int k, delay;
1485
1486         if (NULL == sg_dev_arr)
1487                 return;
1488         delay = 0;
1489         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1490         for (k = 0; k < sg_dev_max; k++) {
1491                 sdp = sg_dev_arr[k];
1492                 if ((NULL == sdp) || (sdp->device != scsidp))
1493                         continue;       /* dirty but lowers nesting */
1494                 if (sdp->headfp) {
1495                         sdp->detached = 1;
1496                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1497                                 tsfp = sfp->nextfp;
1498                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1499                                         tsrp = srp->nextrp;
1500                                         if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1501                                                 sg_finish_rem_req(srp);
1502                                 }
1503                                 if (sfp->closed) {
1504                                         scsi_device_put(sdp->device);
1505                                         __sg_remove_sfp(sdp, sfp);
1506                                 } else {
1507                                         delay = 1;
1508                                         wake_up_interruptible(&sfp->read_wait);
1509                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1510                                                     POLL_HUP);
1511                                 }
1512                         }
1513                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1514                         if (NULL == sdp->headfp) {
1515                                 sg_dev_arr[k] = NULL;
1516                         }
1517                 } else {        /* nothing active, simple case */
1518                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1519                         sg_dev_arr[k] = NULL;
1520                 }
1521                 sg_nr_dev--;
1522                 break;
1523         }
1524         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1525
1526         if (sdp) {
1527                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1528                 class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1529                 cdev_del(sdp->cdev);
1530                 sdp->cdev = NULL;
1531                 put_disk(sdp->disk);
1532                 sdp->disk = NULL;
1533                 if (NULL == sdp->headfp)
1534                         kfree((char *) sdp);
1535         }
1536
1537         if (delay)
1538                 msleep(10);     /* dirty detach so delay device destruction */
1539 }
1540
1541 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1542  * of sysfs parameters (which module_param doesn't yet support).
1543  * Sysfs parameters defined explicitly below.
1544  */
1545 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1546 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1547
1548 MODULE_AUTHOR("Douglas Gilbert");
1549 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1550 MODULE_LICENSE("GPL");
1551 MODULE_VERSION(SG_VERSION_STR);
1552 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1553
1554 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1555 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1556
1557 static int __init
1558 init_sg(void)
1559 {
1560         int rc;
1561
1562         if (def_reserved_size >= 0)
1563                 sg_big_buff = def_reserved_size;
1564
1565         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1566                                     SG_MAX_DEVS, "sg");
1567         if (rc)
1568                 return rc;
1569         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1570         if ( IS_ERR(sg_sysfs_class) ) {
1571                 rc = PTR_ERR(sg_sysfs_class);
1572                 goto err_out;
1573         }
1574         sg_sysfs_valid = 1;
1575         rc = scsi_register_interface(&sg_interface);
1576         if (0 == rc) {
1577 #ifdef CONFIG_SCSI_PROC_FS
1578                 sg_proc_init();
1579 #endif                          /* CONFIG_SCSI_PROC_FS */
1580                 return 0;
1581         }
1582         class_destroy(sg_sysfs_class);
1583 err_out:
1584         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1585         return rc;
1586 }
1587
1588 static void __exit
1589 exit_sg(void)
1590 {
1591 #ifdef CONFIG_SCSI_PROC_FS
1592         sg_proc_cleanup();
1593 #endif                          /* CONFIG_SCSI_PROC_FS */
1594         scsi_unregister_interface(&sg_interface);
1595         class_destroy(sg_sysfs_class);
1596         sg_sysfs_valid = 0;
1597         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1598                                  SG_MAX_DEVS);
1599         kfree((char *)sg_dev_arr);
1600         sg_dev_arr = NULL;
1601         sg_dev_max = 0;
1602 }
1603
1604 static int
1605 sg_start_req(Sg_request * srp)
1606 {
1607         int res;
1608         Sg_fd *sfp = srp->parentfp;
1609         sg_io_hdr_t *hp = &srp->header;
1610         int dxfer_len = (int) hp->dxfer_len;
1611         int dxfer_dir = hp->dxfer_direction;
1612         Sg_scatter_hold *req_schp = &srp->data;
1613         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1614
1615         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1616         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1617                 return 0;
1618         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1619             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1620             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1621                 res = sg_build_direct(srp, sfp, dxfer_len);
1622                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1623                         return res;
1624         }
1625         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1626                 sg_link_reserve(sfp, srp, dxfer_len);
1627         else {
1628                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1629                 if (res) {
1630                         sg_remove_scat(req_schp);
1631                         return res;
1632                 }
1633         }
1634         return 0;
1635 }
1636
1637 static void
1638 sg_finish_rem_req(Sg_request * srp)
1639 {
1640         Sg_fd *sfp = srp->parentfp;
1641         Sg_scatter_hold *req_schp = &srp->data;
1642
1643         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1644         if (srp->res_used)
1645                 sg_unlink_reserve(sfp, srp);
1646         else
1647                 sg_remove_scat(req_schp);
1648         sg_remove_request(sfp, srp);
1649 }
1650
1651 static int
1652 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1653 {
1654         int sg_bufflen = tablesize * sizeof(struct scatterlist);
1655         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1656
1657         /*
1658          * TODO: test without low_dma, we should not need it since
1659          * the block layer will bounce the buffer for us
1660          *
1661          * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1662          */
1663         if (sfp->low_dma)
1664                  gfp_flags |= GFP_DMA;
1665         schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1666         if (!schp->buffer)
1667                 return -ENOMEM;
1668         schp->sglist_len = sg_bufflen;
1669         return tablesize;       /* number of scat_gath elements allocated */
1670 }
1671
1672 #ifdef SG_ALLOW_DIO_CODE
1673 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1674         /* TODO: hopefully we can use the generic block layer code */
1675
1676 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1677    - mapping of all pages not successful
1678    (i.e., either completely successful or fails)
1679 */
1680 static int
1681 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1682                   unsigned long uaddr, size_t count, int rw)
1683 {
1684         unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1685         unsigned long start = uaddr >> PAGE_SHIFT;
1686         const int nr_pages = end - start;
1687         int res, i, j;
1688         struct page **pages;
1689
1690         /* User attempted Overflow! */
1691         if ((uaddr + count) < uaddr)
1692                 return -EINVAL;
1693
1694         /* Too big */
1695         if (nr_pages > max_pages)
1696                 return -ENOMEM;
1697
1698         /* Hmm? */
1699         if (count == 0)
1700                 return 0;
1701
1702         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1703                 return -ENOMEM;
1704
1705         /* Try to fault in all of the necessary pages */
1706         down_read(&current->mm->mmap_sem);
1707         /* rw==READ means read from drive, write into memory area */
1708         res = get_user_pages(
1709                 current,
1710                 current->mm,
1711                 uaddr,
1712                 nr_pages,
1713                 rw == READ,
1714                 0, /* don't force */
1715                 pages,
1716                 NULL);
1717         up_read(&current->mm->mmap_sem);
1718
1719         /* Errors and no page mapped should return here */
1720         if (res < nr_pages)
1721                 goto out_unmap;
1722
1723         for (i=0; i < nr_pages; i++) {
1724                 /* FIXME: flush superflous for rw==READ,
1725                  * probably wrong function for rw==WRITE
1726                  */
1727                 flush_dcache_page(pages[i]);
1728                 /* ?? Is locking needed? I don't think so */
1729                 /* if (TestSetPageLocked(pages[i]))
1730                    goto out_unlock; */
1731         }
1732
1733         sgl[0].page = pages[0];
1734         sgl[0].offset = uaddr & ~PAGE_MASK;
1735         if (nr_pages > 1) {
1736                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1737                 count -= sgl[0].length;
1738                 for (i=1; i < nr_pages ; i++) {
1739                         sgl[i].page = pages[i];
1740                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1741                         count -= PAGE_SIZE;
1742                 }
1743         }
1744         else {
1745                 sgl[0].length = count;
1746         }
1747
1748         kfree(pages);
1749         return nr_pages;
1750
1751  out_unmap:
1752         if (res > 0) {
1753                 for (j=0; j < res; j++)
1754                         page_cache_release(pages[j]);
1755                 res = 0;
1756         }
1757         kfree(pages);
1758         return res;
1759 }
1760
1761
1762 /* And unmap them... */
1763 static int
1764 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1765                     int dirtied)
1766 {
1767         int i;
1768
1769         for (i=0; i < nr_pages; i++) {
1770                 struct page *page = sgl[i].page;
1771
1772                 if (dirtied)
1773                         SetPageDirty(page);
1774                 /* unlock_page(page); */
1775                 /* FIXME: cache flush missing for rw==READ
1776                  * FIXME: call the correct reference counting function
1777                  */
1778                 page_cache_release(page);
1779         }
1780
1781         return 0;
1782 }
1783
1784 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1785 #endif
1786
1787
1788 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1789 static int
1790 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1791 {
1792 #ifdef SG_ALLOW_DIO_CODE
1793         sg_io_hdr_t *hp = &srp->header;
1794         Sg_scatter_hold *schp = &srp->data;
1795         int sg_tablesize = sfp->parentdp->sg_tablesize;
1796         int mx_sc_elems, res;
1797         struct scsi_device *sdev = sfp->parentdp->device;
1798
1799         if (((unsigned long)hp->dxferp &
1800                         queue_dma_alignment(sdev->request_queue)) != 0)
1801                 return 1;
1802
1803         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1804         if (mx_sc_elems <= 0) {
1805                 return 1;
1806         }
1807         res = st_map_user_pages(schp->buffer, mx_sc_elems,
1808                                 (unsigned long)hp->dxferp, dxfer_len,
1809                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1810         if (res <= 0) {
1811                 sg_remove_scat(schp);
1812                 return 1;
1813         }
1814         schp->k_use_sg = res;
1815         schp->dio_in_use = 1;
1816         hp->info |= SG_INFO_DIRECT_IO;
1817         return 0;
1818 #else
1819         return 1;
1820 #endif
1821 }
1822
1823 static int
1824 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1825 {
1826         struct scatterlist *sg;
1827         int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1828         int sg_tablesize = sfp->parentdp->sg_tablesize;
1829         int blk_size = buff_size;
1830         struct page *p = NULL;
1831
1832         if ((blk_size < 0) || (!sfp))
1833                 return -EFAULT;
1834         if (0 == blk_size)
1835                 ++blk_size;     /* don't know why */
1836 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1837         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1838         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1839                                    buff_size, blk_size));
1840
1841         /* N.B. ret_sz carried into this block ... */
1842         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1843         if (mx_sc_elems < 0)
1844                 return mx_sc_elems;     /* most likely -ENOMEM */
1845
1846         for (k = 0, sg = schp->buffer, rem_sz = blk_size;
1847              (rem_sz > 0) && (k < mx_sc_elems);
1848              ++k, rem_sz -= ret_sz, ++sg) {
1849
1850                 num = (rem_sz > SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1851                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1852                 if (!p)
1853                         return -ENOMEM;
1854
1855                 sg->page = p;
1856                 sg->length = ret_sz;
1857
1858                 SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1859                                   k, p, ret_sz));
1860         }               /* end of for loop */
1861
1862         schp->k_use_sg = k;
1863         SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1864
1865         schp->bufflen = blk_size;
1866         if (rem_sz > 0) /* must have failed */
1867                 return -ENOMEM;
1868
1869         return 0;
1870 }
1871
1872 static int
1873 sg_write_xfer(Sg_request * srp)
1874 {
1875         sg_io_hdr_t *hp = &srp->header;
1876         Sg_scatter_hold *schp = &srp->data;
1877         struct scatterlist *sg = schp->buffer;
1878         int num_xfer = 0;
1879         int j, k, onum, usglen, ksglen, res;
1880         int iovec_count = (int) hp->iovec_count;
1881         int dxfer_dir = hp->dxfer_direction;
1882         unsigned char *p;
1883         unsigned char __user *up;
1884         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1885
1886         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1887             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1888                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1889                 if (schp->bufflen < num_xfer)
1890                         num_xfer = schp->bufflen;
1891         }
1892         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1893             (new_interface
1894              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1895                 return 0;
1896
1897         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1898                           num_xfer, iovec_count, schp->k_use_sg));
1899         if (iovec_count) {
1900                 onum = iovec_count;
1901                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1902                         return -EFAULT;
1903         } else
1904                 onum = 1;
1905
1906         ksglen = sg->length;
1907         p = page_address(sg->page);
1908         for (j = 0, k = 0; j < onum; ++j) {
1909                 res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1910                 if (res)
1911                         return res;
1912
1913                 for (; p; ++sg, ksglen = sg->length,
1914                      p = page_address(sg->page)) {
1915                         if (usglen <= 0)
1916                                 break;
1917                         if (ksglen > usglen) {
1918                                 if (usglen >= num_xfer) {
1919                                         if (__copy_from_user(p, up, num_xfer))
1920                                                 return -EFAULT;
1921                                         return 0;
1922                                 }
1923                                 if (__copy_from_user(p, up, usglen))
1924                                         return -EFAULT;
1925                                 p += usglen;
1926                                 ksglen -= usglen;
1927                                 break;
1928                         } else {
1929                                 if (ksglen >= num_xfer) {
1930                                         if (__copy_from_user(p, up, num_xfer))
1931                                                 return -EFAULT;
1932                                         return 0;
1933                                 }
1934                                 if (__copy_from_user(p, up, ksglen))
1935                                         return -EFAULT;
1936                                 up += ksglen;
1937                                 usglen -= ksglen;
1938                         }
1939                         ++k;
1940                         if (k >= schp->k_use_sg)
1941                                 return 0;
1942                 }
1943         }
1944
1945         return 0;
1946 }
1947
1948 static int
1949 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1950            int wr_xf, int *countp, unsigned char __user **up)
1951 {
1952         int num_xfer = (int) hp->dxfer_len;
1953         unsigned char __user *p = hp->dxferp;
1954         int count;
1955
1956         if (0 == sg_num) {
1957                 if (wr_xf && ('\0' == hp->interface_id))
1958                         count = (int) hp->flags;        /* holds "old" input_size */
1959                 else
1960                         count = num_xfer;
1961         } else {
1962                 sg_iovec_t iovec;
1963                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1964                         return -EFAULT;
1965                 p = iovec.iov_base;
1966                 count = (int) iovec.iov_len;
1967         }
1968         if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
1969                 return -EFAULT;
1970         if (up)
1971                 *up = p;
1972         if (countp)
1973                 *countp = count;
1974         return 0;
1975 }
1976
1977 static void
1978 sg_remove_scat(Sg_scatter_hold * schp)
1979 {
1980         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1981         if (schp->buffer && (schp->sglist_len > 0)) {
1982                 struct scatterlist *sg = schp->buffer;
1983
1984                 if (schp->dio_in_use) {
1985 #ifdef SG_ALLOW_DIO_CODE
1986                         st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
1987 #endif
1988                 } else {
1989                         int k;
1990
1991                         for (k = 0; (k < schp->k_use_sg) && sg->page;
1992                              ++k, ++sg) {
1993                                 SCSI_LOG_TIMEOUT(5, printk(
1994                                     "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
1995                                     k, sg->page, sg->length));
1996                                 sg_page_free(sg->page, sg->length);
1997                         }
1998                 }
1999                 kfree(schp->buffer);
2000         }
2001         memset(schp, 0, sizeof (*schp));
2002 }
2003
2004 static int
2005 sg_read_xfer(Sg_request * srp)
2006 {
2007         sg_io_hdr_t *hp = &srp->header;
2008         Sg_scatter_hold *schp = &srp->data;
2009         struct scatterlist *sg = schp->buffer;
2010         int num_xfer = 0;
2011         int j, k, onum, usglen, ksglen, res;
2012         int iovec_count = (int) hp->iovec_count;
2013         int dxfer_dir = hp->dxfer_direction;
2014         unsigned char *p;
2015         unsigned char __user *up;
2016         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2017
2018         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2019             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2020                 num_xfer = hp->dxfer_len;
2021                 if (schp->bufflen < num_xfer)
2022                         num_xfer = schp->bufflen;
2023         }
2024         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2025             (new_interface
2026              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2027                 return 0;
2028
2029         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2030                           num_xfer, iovec_count, schp->k_use_sg));
2031         if (iovec_count) {
2032                 onum = iovec_count;
2033                 if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2034                         return -EFAULT;
2035         } else
2036                 onum = 1;
2037
2038         p = page_address(sg->page);
2039         ksglen = sg->length;
2040         for (j = 0, k = 0; j < onum; ++j) {
2041                 res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2042                 if (res)
2043                         return res;
2044
2045                 for (; p; ++sg, ksglen = sg->length,
2046                      p = page_address(sg->page)) {
2047                         if (usglen <= 0)
2048                                 break;
2049                         if (ksglen > usglen) {
2050                                 if (usglen >= num_xfer) {
2051                                         if (__copy_to_user(up, p, num_xfer))
2052                                                 return -EFAULT;
2053                                         return 0;
2054                                 }
2055                                 if (__copy_to_user(up, p, usglen))
2056                                         return -EFAULT;
2057                                 p += usglen;
2058                                 ksglen -= usglen;
2059                                 break;
2060                         } else {
2061                                 if (ksglen >= num_xfer) {
2062                                         if (__copy_to_user(up, p, num_xfer))
2063                                                 return -EFAULT;
2064                                         return 0;
2065                                 }
2066                                 if (__copy_to_user(up, p, ksglen))
2067                                         return -EFAULT;
2068                                 up += ksglen;
2069                                 usglen -= ksglen;
2070                         }
2071                         ++k;
2072                         if (k >= schp->k_use_sg)
2073                                 return 0;
2074                 }
2075         }
2076
2077         return 0;
2078 }
2079
2080 static int
2081 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2082 {
2083         Sg_scatter_hold *schp = &srp->data;
2084         struct scatterlist *sg = schp->buffer;
2085         int k, num;
2086
2087         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2088                                    num_read_xfer));
2089         if ((!outp) || (num_read_xfer <= 0))
2090                 return 0;
2091
2092         for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
2093                 num = sg->length;
2094                 if (num > num_read_xfer) {
2095                         if (__copy_to_user(outp, page_address(sg->page),
2096                                            num_read_xfer))
2097                                 return -EFAULT;
2098                         break;
2099                 } else {
2100                         if (__copy_to_user(outp, page_address(sg->page),
2101                                            num))
2102                                 return -EFAULT;
2103                         num_read_xfer -= num;
2104                         if (num_read_xfer <= 0)
2105                                 break;
2106                         outp += num;
2107                 }
2108         }
2109
2110         return 0;
2111 }
2112
2113 static void
2114 sg_build_reserve(Sg_fd * sfp, int req_size)
2115 {
2116         Sg_scatter_hold *schp = &sfp->reserve;
2117
2118         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2119         do {
2120                 if (req_size < PAGE_SIZE)
2121                         req_size = PAGE_SIZE;
2122                 if (0 == sg_build_indirect(schp, sfp, req_size))
2123                         return;
2124                 else
2125                         sg_remove_scat(schp);
2126                 req_size >>= 1; /* divide by 2 */
2127         } while (req_size > (PAGE_SIZE / 2));
2128 }
2129
2130 static void
2131 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2132 {
2133         Sg_scatter_hold *req_schp = &srp->data;
2134         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2135         struct scatterlist *sg = rsv_schp->buffer;
2136         int k, num, rem;
2137
2138         srp->res_used = 1;
2139         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2140         rem = size;
2141
2142         for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
2143                 num = sg->length;
2144                 if (rem <= num) {
2145                         sfp->save_scat_len = num;
2146                         sg->length = rem;
2147                         req_schp->k_use_sg = k + 1;
2148                         req_schp->sglist_len = rsv_schp->sglist_len;
2149                         req_schp->buffer = rsv_schp->buffer;
2150
2151                         req_schp->bufflen = size;
2152                         req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2153                         break;
2154                 } else
2155                         rem -= num;
2156         }
2157
2158         if (k >= rsv_schp->k_use_sg)
2159                 SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2160 }
2161
2162 static void
2163 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2164 {
2165         Sg_scatter_hold *req_schp = &srp->data;
2166         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2167
2168         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2169                                    (int) req_schp->k_use_sg));
2170         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2171                 struct scatterlist *sg = rsv_schp->buffer;
2172
2173                 if (sfp->save_scat_len > 0)
2174                         (sg + (req_schp->k_use_sg - 1))->length =
2175                             (unsigned) sfp->save_scat_len;
2176                 else
2177                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2178         }
2179         req_schp->k_use_sg = 0;
2180         req_schp->bufflen = 0;
2181         req_schp->buffer = NULL;
2182         req_schp->sglist_len = 0;
2183         sfp->save_scat_len = 0;
2184         srp->res_used = 0;
2185 }
2186
2187 static Sg_request *
2188 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2189 {
2190         Sg_request *resp;
2191         unsigned long iflags;
2192
2193         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2194         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2195                 /* look for requests that are ready + not SG_IO owned */
2196                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2197                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2198                         resp->done = 2; /* guard against other readers */
2199                         break;
2200                 }
2201         }
2202         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2203         return resp;
2204 }
2205
2206 #ifdef CONFIG_SCSI_PROC_FS
2207 static Sg_request *
2208 sg_get_nth_request(Sg_fd * sfp, int nth)
2209 {
2210         Sg_request *resp;
2211         unsigned long iflags;
2212         int k;
2213
2214         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2215         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2216              ++k, resp = resp->nextrp) ;
2217         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2218         return resp;
2219 }
2220 #endif
2221
2222 /* always adds to end of list */
2223 static Sg_request *
2224 sg_add_request(Sg_fd * sfp)
2225 {
2226         int k;
2227         unsigned long iflags;
2228         Sg_request *resp;
2229         Sg_request *rp = sfp->req_arr;
2230
2231         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2232         resp = sfp->headrp;
2233         if (!resp) {
2234                 memset(rp, 0, sizeof (Sg_request));
2235                 rp->parentfp = sfp;
2236                 resp = rp;
2237                 sfp->headrp = resp;
2238         } else {
2239                 if (0 == sfp->cmd_q)
2240                         resp = NULL;    /* command queuing disallowed */
2241                 else {
2242                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2243                                 if (!rp->parentfp)
2244                                         break;
2245                         }
2246                         if (k < SG_MAX_QUEUE) {
2247                                 memset(rp, 0, sizeof (Sg_request));
2248                                 rp->parentfp = sfp;
2249                                 while (resp->nextrp)
2250                                         resp = resp->nextrp;
2251                                 resp->nextrp = rp;
2252                                 resp = rp;
2253                         } else
2254                                 resp = NULL;
2255                 }
2256         }
2257         if (resp) {
2258                 resp->nextrp = NULL;
2259                 resp->header.duration = jiffies_to_msecs(jiffies);
2260         }
2261         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2262         return resp;
2263 }
2264
2265 /* Return of 1 for found; 0 for not found */
2266 static int
2267 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2268 {
2269         Sg_request *prev_rp;
2270         Sg_request *rp;
2271         unsigned long iflags;
2272         int res = 0;
2273
2274         if ((!sfp) || (!srp) || (!sfp->headrp))
2275                 return res;
2276         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2277         prev_rp = sfp->headrp;
2278         if (srp == prev_rp) {
2279                 sfp->headrp = prev_rp->nextrp;
2280                 prev_rp->parentfp = NULL;
2281                 res = 1;
2282         } else {
2283                 while ((rp = prev_rp->nextrp)) {
2284                         if (srp == rp) {
2285                                 prev_rp->nextrp = rp->nextrp;
2286                                 rp->parentfp = NULL;
2287                                 res = 1;
2288                                 break;
2289                         }
2290                         prev_rp = rp;
2291                 }
2292         }
2293         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2294         return res;
2295 }
2296
2297 #ifdef CONFIG_SCSI_PROC_FS
2298 static Sg_fd *
2299 sg_get_nth_sfp(Sg_device * sdp, int nth)
2300 {
2301         Sg_fd *resp;
2302         unsigned long iflags;
2303         int k;
2304
2305         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2306         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2307              ++k, resp = resp->nextfp) ;
2308         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2309         return resp;
2310 }
2311 #endif
2312
2313 static Sg_fd *
2314 sg_add_sfp(Sg_device * sdp, int dev)
2315 {
2316         Sg_fd *sfp;
2317         unsigned long iflags;
2318
2319         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2320         if (!sfp)
2321                 return NULL;
2322
2323         init_waitqueue_head(&sfp->read_wait);
2324         rwlock_init(&sfp->rq_list_lock);
2325
2326         sfp->timeout = SG_DEFAULT_TIMEOUT;
2327         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2328         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2329         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2330             sdp->device->host->unchecked_isa_dma : 1;
2331         sfp->cmd_q = SG_DEF_COMMAND_Q;
2332         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2333         sfp->parentdp = sdp;
2334         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2335         if (!sdp->headfp)
2336                 sdp->headfp = sfp;
2337         else {                  /* add to tail of existing list */
2338                 Sg_fd *pfp = sdp->headfp;
2339                 while (pfp->nextfp)
2340                         pfp = pfp->nextfp;
2341                 pfp->nextfp = sfp;
2342         }
2343         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2344         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2345         sg_build_reserve(sfp, sg_big_buff);
2346         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2347                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2348         return sfp;
2349 }
2350
2351 static void
2352 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2353 {
2354         Sg_fd *fp;
2355         Sg_fd *prev_fp;
2356
2357         prev_fp = sdp->headfp;
2358         if (sfp == prev_fp)
2359                 sdp->headfp = prev_fp->nextfp;
2360         else {
2361                 while ((fp = prev_fp->nextfp)) {
2362                         if (sfp == fp) {
2363                                 prev_fp->nextfp = fp->nextfp;
2364                                 break;
2365                         }
2366                         prev_fp = fp;
2367                 }
2368         }
2369         if (sfp->reserve.bufflen > 0) {
2370                 SCSI_LOG_TIMEOUT(6,
2371                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2372                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2373                 sg_remove_scat(&sfp->reserve);
2374         }
2375         sfp->parentdp = NULL;
2376         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2377         kfree(sfp);
2378 }
2379
2380 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2381 static int
2382 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2383 {
2384         Sg_request *srp;
2385         Sg_request *tsrp;
2386         int dirty = 0;
2387         int res = 0;
2388
2389         for (srp = sfp->headrp; srp; srp = tsrp) {
2390                 tsrp = srp->nextrp;
2391                 if (sg_srp_done(srp, sfp))
2392                         sg_finish_rem_req(srp);
2393                 else
2394                         ++dirty;
2395         }
2396         if (0 == dirty) {
2397                 unsigned long iflags;
2398
2399                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2400                 __sg_remove_sfp(sdp, sfp);
2401                 if (sdp->detached && (NULL == sdp->headfp)) {
2402                         int k, maxd;
2403
2404                         maxd = sg_dev_max;
2405                         for (k = 0; k < maxd; ++k) {
2406                                 if (sdp == sg_dev_arr[k])
2407                                         break;
2408                         }
2409                         if (k < maxd)
2410                                 sg_dev_arr[k] = NULL;
2411                         kfree((char *) sdp);
2412                         res = 1;
2413                 }
2414                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2415         } else {
2416                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2417                 /* only bump the access_count if we actually succeeded in
2418                  * throwing another counter on the host module */
2419                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2420                 sfp->closed = 1;        /* flag dirty state on this fd */
2421                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2422                                   dirty));
2423         }
2424         return res;
2425 }
2426
2427 static int
2428 sg_res_in_use(Sg_fd * sfp)
2429 {
2430         const Sg_request *srp;
2431         unsigned long iflags;
2432
2433         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2434         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2435                 if (srp->res_used)
2436                         break;
2437         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2438         return srp ? 1 : 0;
2439 }
2440
2441 /* If retSzp==NULL want exact size or fail */
2442 static struct page *
2443 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2444 {
2445         struct page *resp = NULL;
2446         gfp_t page_mask;
2447         int order, a_size;
2448         int resSz = rqSz;
2449
2450         if (rqSz <= 0)
2451                 return resp;
2452
2453         if (lowDma)
2454                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
2455         else
2456                 page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
2457
2458         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2459              order++, a_size <<= 1) ;
2460         resp = alloc_pages(page_mask, order);
2461         while ((!resp) && order && retSzp) {
2462                 --order;
2463                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2464                 resp =  alloc_pages(page_mask, order);  /* try half */
2465                 resSz = a_size;
2466         }
2467         if (resp) {
2468                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2469                         memset(page_address(resp), 0, resSz);
2470                 if (retSzp)
2471                         *retSzp = resSz;
2472         }
2473         return resp;
2474 }
2475
2476 static void
2477 sg_page_free(struct page *page, int size)
2478 {
2479         int order, a_size;
2480
2481         if (!page)
2482                 return;
2483         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2484              order++, a_size <<= 1) ;
2485         __free_pages(page, order);
2486 }
2487
2488 #ifndef MAINTENANCE_IN_CMD
2489 #define MAINTENANCE_IN_CMD 0xa3
2490 #endif
2491
2492 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2493         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2494         READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2495         SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2496 };
2497
2498 static int
2499 sg_allow_access(unsigned char opcode, char dev_type)
2500 {
2501         int k;
2502
2503         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2504                 return 1;
2505         for (k = 0; k < sizeof (allow_ops); ++k) {
2506                 if (opcode == allow_ops[k])
2507                         return 1;
2508         }
2509         return 0;
2510 }
2511
2512 #ifdef CONFIG_SCSI_PROC_FS
2513 static int
2514 sg_last_dev(void)
2515 {
2516         int k;
2517         unsigned long iflags;
2518
2519         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2520         for (k = sg_dev_max - 1; k >= 0; --k)
2521                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2522                         break;
2523         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2524         return k + 1;           /* origin 1 */
2525 }
2526 #endif
2527
2528 static Sg_device *
2529 sg_get_dev(int dev)
2530 {
2531         Sg_device *sdp = NULL;
2532         unsigned long iflags;
2533
2534         if (sg_dev_arr && (dev >= 0)) {
2535                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2536                 if (dev < sg_dev_max)
2537                         sdp = sg_dev_arr[dev];
2538                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2539         }
2540         return sdp;
2541 }
2542
2543 #ifdef CONFIG_SCSI_PROC_FS
2544
2545 static struct proc_dir_entry *sg_proc_sgp = NULL;
2546
2547 static char sg_proc_sg_dirname[] = "scsi/sg";
2548
2549 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2550
2551 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2552 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2553                                   size_t count, loff_t *off);
2554 static struct file_operations adio_fops = {
2555         /* .owner, .read and .llseek added in sg_proc_init() */
2556         .open = sg_proc_single_open_adio,
2557         .write = sg_proc_write_adio,
2558         .release = single_release,
2559 };
2560
2561 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2562 static ssize_t sg_proc_write_dressz(struct file *filp,
2563                 const char __user *buffer, size_t count, loff_t *off);
2564 static struct file_operations dressz_fops = {
2565         .open = sg_proc_single_open_dressz,
2566         .write = sg_proc_write_dressz,
2567         .release = single_release,
2568 };
2569
2570 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2571 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2572 static struct file_operations version_fops = {
2573         .open = sg_proc_single_open_version,
2574         .release = single_release,
2575 };
2576
2577 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2578 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2579 static struct file_operations devhdr_fops = {
2580         .open = sg_proc_single_open_devhdr,
2581         .release = single_release,
2582 };
2583
2584 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2585 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2586 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2587 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2588 static void dev_seq_stop(struct seq_file *s, void *v);
2589 static struct file_operations dev_fops = {
2590         .open = sg_proc_open_dev,
2591         .release = seq_release,
2592 };
2593 static struct seq_operations dev_seq_ops = {
2594         .start = dev_seq_start,
2595         .next  = dev_seq_next,
2596         .stop  = dev_seq_stop,
2597         .show  = sg_proc_seq_show_dev,
2598 };
2599
2600 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2601 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2602 static struct file_operations devstrs_fops = {
2603         .open = sg_proc_open_devstrs,
2604         .release = seq_release,
2605 };
2606 static struct seq_operations devstrs_seq_ops = {
2607         .start = dev_seq_start,
2608         .next  = dev_seq_next,
2609         .stop  = dev_seq_stop,
2610         .show  = sg_proc_seq_show_devstrs,
2611 };
2612
2613 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2614 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2615 static struct file_operations debug_fops = {
2616         .open = sg_proc_open_debug,
2617         .release = seq_release,
2618 };
2619 static struct seq_operations debug_seq_ops = {
2620         .start = dev_seq_start,
2621         .next  = dev_seq_next,
2622         .stop  = dev_seq_stop,
2623         .show  = sg_proc_seq_show_debug,
2624 };
2625
2626
2627 struct sg_proc_leaf {
2628         const char * name;
2629         struct file_operations * fops;
2630 };
2631
2632 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2633         {"allow_dio", &adio_fops},
2634         {"debug", &debug_fops},
2635         {"def_reserved_size", &dressz_fops},
2636         {"device_hdr", &devhdr_fops},
2637         {"devices", &dev_fops},
2638         {"device_strs", &devstrs_fops},
2639         {"version", &version_fops}
2640 };
2641
2642 static int
2643 sg_proc_init(void)
2644 {
2645         int k, mask;
2646         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2647         struct proc_dir_entry *pdep;
2648         struct sg_proc_leaf * leaf;
2649
2650         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2651         if (!sg_proc_sgp)
2652                 return 1;
2653         for (k = 0; k < num_leaves; ++k) {
2654                 leaf = &sg_proc_leaf_arr[k];
2655                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2656                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2657                 if (pdep) {
2658                         leaf->fops->owner = THIS_MODULE,
2659                         leaf->fops->read = seq_read,
2660                         leaf->fops->llseek = seq_lseek,
2661                         pdep->proc_fops = leaf->fops;
2662                 }
2663         }
2664         return 0;
2665 }
2666
2667 static void
2668 sg_proc_cleanup(void)
2669 {
2670         int k;
2671         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2672
2673         if (!sg_proc_sgp)
2674                 return;
2675         for (k = 0; k < num_leaves; ++k)
2676                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2677         remove_proc_entry(sg_proc_sg_dirname, NULL);
2678 }
2679
2680
2681 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2682 {
2683         seq_printf(s, "%d\n", *((int *)s->private));
2684         return 0;
2685 }
2686
2687 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2688 {
2689         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2690 }
2691
2692 static ssize_t
2693 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2694                    size_t count, loff_t *off)
2695 {
2696         int num;
2697         char buff[11];
2698
2699         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2700                 return -EACCES;
2701         num = (count < 10) ? count : 10;
2702         if (copy_from_user(buff, buffer, num))
2703                 return -EFAULT;
2704         buff[num] = '\0';
2705         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2706         return count;
2707 }
2708
2709 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2710 {
2711         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2712 }
2713
2714 static ssize_t
2715 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2716                      size_t count, loff_t *off)
2717 {
2718         int num;
2719         unsigned long k = ULONG_MAX;
2720         char buff[11];
2721
2722         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2723                 return -EACCES;
2724         num = (count < 10) ? count : 10;
2725         if (copy_from_user(buff, buffer, num))
2726                 return -EFAULT;
2727         buff[num] = '\0';
2728         k = simple_strtoul(buff, NULL, 10);
2729         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2730                 sg_big_buff = k;
2731                 return count;
2732         }
2733         return -ERANGE;
2734 }
2735
2736 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2737 {
2738         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2739                    sg_version_date);
2740         return 0;
2741 }
2742
2743 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2744 {
2745         return single_open(file, sg_proc_seq_show_version, NULL);
2746 }
2747
2748 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2749 {
2750         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2751                    "online\n");
2752         return 0;
2753 }
2754
2755 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2756 {
2757         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2758 }
2759
2760 struct sg_proc_deviter {
2761         loff_t  index;
2762         size_t  max;
2763 };
2764
2765 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2766 {
2767         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2768
2769         s->private = it;
2770         if (! it)
2771                 return NULL;
2772
2773         if (NULL == sg_dev_arr)
2774                 return NULL;
2775         it->index = *pos;
2776         it->max = sg_last_dev();
2777         if (it->index >= it->max)
2778                 return NULL;
2779         return it;
2780 }
2781
2782 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2783 {
2784         struct sg_proc_deviter * it = s->private;
2785
2786         *pos = ++it->index;
2787         return (it->index < it->max) ? it : NULL;
2788 }
2789
2790 static void dev_seq_stop(struct seq_file *s, void *v)
2791 {
2792         kfree(s->private);
2793 }
2794
2795 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2796 {
2797         return seq_open(file, &dev_seq_ops);
2798 }
2799
2800 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2801 {
2802         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2803         Sg_device *sdp;
2804         struct scsi_device *scsidp;
2805
2806         sdp = it ? sg_get_dev(it->index) : NULL;
2807         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2808                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2809                               scsidp->host->host_no, scsidp->channel,
2810                               scsidp->id, scsidp->lun, (int) scsidp->type,
2811                               1,
2812                               (int) scsidp->queue_depth,
2813                               (int) scsidp->device_busy,
2814                               (int) scsi_device_online(scsidp));
2815         else
2816                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2817         return 0;
2818 }
2819
2820 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2821 {
2822         return seq_open(file, &devstrs_seq_ops);
2823 }
2824
2825 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2826 {
2827         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2828         Sg_device *sdp;
2829         struct scsi_device *scsidp;
2830
2831         sdp = it ? sg_get_dev(it->index) : NULL;
2832         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2833                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2834                            scsidp->vendor, scsidp->model, scsidp->rev);
2835         else
2836                 seq_printf(s, "<no active device>\n");
2837         return 0;
2838 }
2839
2840 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2841 {
2842         int k, m, new_interface, blen, usg;
2843         Sg_request *srp;
2844         Sg_fd *fp;
2845         const sg_io_hdr_t *hp;
2846         const char * cp;
2847         unsigned int ms;
2848
2849         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2850                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2851                            "(res)sgat=%d low_dma=%d\n", k + 1,
2852                            jiffies_to_msecs(fp->timeout),
2853                            fp->reserve.bufflen,
2854                            (int) fp->reserve.k_use_sg,
2855                            (int) fp->low_dma);
2856                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2857                            (int) fp->cmd_q, (int) fp->force_packid,
2858                            (int) fp->keep_orphan, (int) fp->closed);
2859                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2860                         hp = &srp->header;
2861                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2862                         if (srp->res_used) {
2863                                 if (new_interface &&
2864                                     (SG_FLAG_MMAP_IO & hp->flags))
2865                                         cp = "     mmap>> ";
2866                                 else
2867                                         cp = "     rb>> ";
2868                         } else {
2869                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2870                                         cp = "     dio>> ";
2871                                 else
2872                                         cp = "     ";
2873                         }
2874                         seq_printf(s, cp);
2875                         blen = srp->data.bufflen;
2876                         usg = srp->data.k_use_sg;
2877                         seq_printf(s, srp->done ?
2878                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2879                                    : "act:");
2880                         seq_printf(s, " id=%d blen=%d",
2881                                    srp->header.pack_id, blen);
2882                         if (srp->done)
2883                                 seq_printf(s, " dur=%d", hp->duration);
2884                         else {
2885                                 ms = jiffies_to_msecs(jiffies);
2886                                 seq_printf(s, " t_o/elap=%d/%d",
2887                                         (new_interface ? hp->timeout :
2888                                                   jiffies_to_msecs(fp->timeout)),
2889                                         (ms > hp->duration ? ms - hp->duration : 0));
2890                         }
2891                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2892                                    (int) srp->data.cmd_opcode);
2893                 }
2894                 if (0 == m)
2895                         seq_printf(s, "     No requests active\n");
2896         }
2897 }
2898
2899 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2900 {
2901         return seq_open(file, &debug_seq_ops);
2902 }
2903
2904 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2905 {
2906         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2907         Sg_device *sdp;
2908
2909         if (it && (0 == it->index)) {
2910                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
2911                            "(origin 1)\n", sg_dev_max, (int)it->max);
2912                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2913         }
2914         sdp = it ? sg_get_dev(it->index) : NULL;
2915         if (sdp) {
2916                 struct scsi_device *scsidp = sdp->device;
2917
2918                 if (NULL == scsidp) {
2919                         seq_printf(s, "device %d detached ??\n",
2920                                    (int)it->index);
2921                         return 0;
2922                 }
2923
2924                 if (sg_get_nth_sfp(sdp, 0)) {
2925                         seq_printf(s, " >>> device=%s ",
2926                                 sdp->disk->disk_name);
2927                         if (sdp->detached)
2928                                 seq_printf(s, "detached pending close ");
2929                         else
2930                                 seq_printf
2931                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2932                                      scsidp->host->host_no,
2933                                      scsidp->channel, scsidp->id,
2934                                      scsidp->lun,
2935                                      scsidp->host->hostt->emulated);
2936                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
2937                                    sdp->sg_tablesize, sdp->exclude);
2938                 }
2939                 sg_proc_debug_helper(s, sdp);
2940         }
2941         return 0;
2942 }
2943
2944 #endif                          /* CONFIG_SCSI_PROC_FS */
2945
2946 module_init(init_sg);
2947 module_exit(exit_sg);